What is normal blood sugar level
Blood sugar and blood sugar are interchangeable terms, and both are crucial to the health of the body; especially for people with diabetes. Blood glucose is the primary energy source for the body’s cells and the only energy source for the brain and nervous system. A steady supply must be available for use, and a relatively constant level of glucose must be maintained in the blood. A few different protocols may be used to evaluate the blood sugar (glucose level) in the blood. See “Blood sugar test” for more information on these. Sometimes, glucose may be tested in urine.
- Blood glucose typically varies from 70.2 mg/dL to 99 mg/dL (3.5 mmol/L to 5.5 mmol/L) for people without diabetes.
During digestion, fruits, vegetables, breads and other dietary sources of carbohydrates are broken down into glucose (and other nutrients); they are absorbed by the small intestine and circulated throughout the body. Using glucose for energy production depends on insulin, a hormone produced by the pancreas. Insulin facilitates transport of glucose into the body’s cells and directs the liver to store excess energy as glycogen for short-term storage and/or as triglycerides in adipose (fat) cells.
For the majority of healthy individuals, normal blood sugar levels are as follows:
- Fasting: between 70.2 to 99 mg/dL (3.9 to 5.5 mmol/L)
- 2 hours after eating: up to 140 mg/dL (7.8 mmol/L)
Normally, blood glucose rises slightly after a meal and insulin is released by the pancreas into the blood in response, with the amount corresponding to the size and content of the meal. As glucose moves into the cells and is metabolized, the level in the blood drops and the pancreas responds by slowing, then stopping the release of insulin.
If the blood glucose level drops too low – hypoglycemia, such as might occur in between meals or after a strenuous workout, glucagon (another pancreatic hormone) is secreted to induce the liver to turn some glycogen back into glucose, raising the blood glucose level. If the glucose/insulin feedback mechanism is working properly, the amount of glucose in the blood remains fairly stable. If the balance is disrupted and the glucose level in the blood rises, then the body tries to restore the balance, both by increasing insulin production and by eliminating excess glucose in the urine.
Table 1. Fasting blood glucose – this measures the level of glucose in your blood after an 8-12 hour fast.
Fasting Glucose Level | Indication |
Less than 70 mg/dL (3.9 mmol/L) | Hypoglycemia |
From 70 to 99 mg/dL (3.9 to 5.5 mmol/L) | Normal fasting glucose |
From 100 to 125 mg/dL (5.6 to 6.9 mmol/L) | Prediabetes (impaired fasting glucose) |
126 mg/dL (7.0 mmol/L) and above on more than one testing occasion | Diabetes |
Greater than 200 mg/dL (greater than 11.1 mmol/L) | Hyperglycemia |
Note: The American Diabetes Association suggests the following targets for most nonpregnant adults with diabetes. More or less stringent glycemic goals may be appropriate for each individual.
- Before a meal (preprandial plasma glucose): 80–130 mg/dl (4.4- 7.2 mmol/L ) and
- 1-2 hours after beginning of the meal (Postprandial plasma glucose): Less than 180 mg/dl (less than 10 mmol/L)
There are a few different conditions that may disrupt the balance between glucose and the pancreatic hormones, resulting in high or low blood glucose. The most common cause is diabetes. Diabetes is a group of disorders associated with insufficient insulin production and/or a resistance to the effects of insulin. People with untreated diabetes are not able to process and use glucose normally. Those who are not able to produce any or enough insulin (and typically have diabetes autoantibodies) are diagnosed as having type 1 diabetes. Those who are resistant to insulin and may or may not be able to produce sufficient quantities of it may have prediabetes or type 2 diabetes.
Severe, acute changes in blood glucose, either high (hyperglycemia) or low (hypoglycemia), can be life-threatening, causing organ failure, brain damage, coma, and, in extreme cases, death. Chronically high blood glucose levels can cause progressive damage to body organs such as the kidneys, eyes, heart and blood vessels, and nerves. Chronic hypoglycemia can lead to brain and nerve damage.
Some women may develop gestational diabetes, which is hyperglycemia that occurs only during pregnancy. If untreated, this can cause these mothers to give birth to large babies who may have low glucose levels. Women who have had gestational diabetes may or may not go on to develop diabetes.
Factors Affecting Blood Glucose
Before you had diabetes, no matter what you ate or how active you were, your blood glucose levels stayed within a normal range. But with diabetes, your blood glucose level can rise higher and some diabetes medications can make them go lower than normal. Many factors can change your blood glucose levels. Learning about these can help control your blood glucose levels.
You can use your blood glucose (blood sugar) levels to make decisions about food and activity. These decisions can help you delay or prevent diabetes complications such as heart attack, kidney disease, blindness, and amputation.
What can make my blood glucose rise?
- Too much food, like a meal or snack with more carbohydrates than usual
- Not being active
- Not enough insulin or oral diabetes medications
- Side effects from other medications, such as steroids, anti-psychotic medications
- Illness – your body releases hormones to fight the illness, and those hormones raise blood glucose levels
- Stress, which can produce hormones that raise blood glucose levels
- Short- or long-term pain, like pain from a sunburn – your body releases hormones that raise glucose levels
- Menstrual periods, which cause changes in hormone levels
- Dehydration
What can make my blood glucose fall?
- Not enough food, like a meal or snack with fewer carbohydrates than usual, missing a meal or snack
- Alcohol, especially on an empty stomach
- Too much insulin or oral diabetes medications
- Side effects from other medications
- More physical activity or exercise than usual – physical activity makes your body more sensitive to insulin and can lower blood glucose.
What are blood sugar levels
Blood sugar levels are literally the amount of glucose in the blood, sometimes called the serum glucose level. Usually, this amount is expressed as millimoles per litre (mmol/L) or milligrams per decilitre (mg/dL) or [milligrams per 100 millilitres] and stay stable amongst people without diabetes at around 4-6 mmol/L (72-108 mg/dL).
Spikes in blood sugar will occur following meals, and levels will usually be at their lowest in the early mornings. When it comes to people with diabetes, blood sugar fluctuates more widely.
How convert mg/dL to mmol/L or mmol/L to mg/dL
Most often used measurement conversion
- mmol per L to mg per dL converter: 1 mmol/L is equal 18 mg /dL or mg/dL / 18
- mg per dL to mmol per L converter: 1 mg/dL is equal 0.055555555555556 mmol/L [millimoles per litre]
Whats the difference between mmol/L and mg/dL?
Both sets of units are used to measure blood sugar levels and both give a measurement of the concentration of glucose in the blood, albeit in slightly different ways.
mmol/L gives the molarity, which is the number of molecules of a substance within a specified volume, in this case within 1 litre. mg/dL gives the concentration by the ratio of weight to volume, in this case milligrams per decilitre.
mmol/L is the most common measurement used in the UK with mg/dL predominantly used in the USA and continental Europe.
- mmol/L International standard unit for measuring the concentration of glucose in the blood – also known as millimolar (mM). This unit is used in the UK, Australia and NZ.: Millimoles per litre
- mg/dL Unit for measuring concentration of glucose in the blood in the USA – milligrams per decilitre: Milligrams per 100 millilitres
Blood sugar level ranges
Understanding blood glucose level ranges can be a key part of diabetes self-management.
This page states ‘normal’ blood sugar ranges and blood sugar ranges for adults and children with type 1 diabetes, type 2 diabetes and blood sugar ranges to determine people with diabetes.
If a person with diabetes has a meter, test strips and is testing, it’s important to know what the blood glucose level means.
Recommended blood glucose levels have a degree of interpretation for every individual and you should discuss this with your healthcare team.
In addition, women may be set target blood sugar levels during pregnancy.
The following ranges are guidelines provided by the National Institute for Clinical Excellence 1, 2 but each individual’s target range should be agreed by their doctor or diabetic consultant.
Recommended target blood glucose level ranges
The National Institute for Clinical Excellence (NICE) 1, 2 recommended target blood glucose levels are stated below for adults with type 1 diabetes, type 2 diabetes and children with type 1 diabetes.
In addition, the International Diabetes Federation’s target ranges for people without diabetes is stated 3.
The table provides general guidance. An individual target set by your healthcare team is the one you should aim for.
Table 2. National Institute for Clinical Excellence recommended target blood glucose level ranges
Target Levels by Type | Upon waking | Before meals (pre prandial) | At least 90 minutes after meals (post prandial) |
---|---|---|---|
Non-diabetic* | 70.2 to 99 mg/dL (3.9 to 5.5 mmol/L) | under 140.4 mg/dL (under 7.8 mmol/L) | |
Type 2 diabetes | 72 to 126 mg/dL (4 to 7 mmol/L) | under 153 mg/dL (under 8.5 mmol/L) | |
Type 1 diabetes | 90 to 126 mg/dL (5 to 7 mmol/L) | 72 to 126 mg/dL (4 to 7 mmol/L) | 90 to 162 mg/dL (5 to 9 mmol/L) |
Children w/ type 1 diabetes | 72 to 126 mg/dL (4 to 7 mmol/L) | 72 to 126 mg/dL (4 to 7 mmol/L) | 90 to 162 mg/dL (5 to 9 mmol/L) |
*The non-diabetic figures are provided for information but are not part of NICE guidelines.
[Source 4]Normal and diabetic blood sugar ranges
For the majority of healthy individuals, normal blood sugar levels are as follows:
- Between 70.2 to 99 mg/dL (3.9 to 5.5 mmol/L) when fasting
- Up to 140 mg/dL (7.8 mmol/L) 2 hours after eating
For people with diabetes, blood sugar level targets are as follows:
- Before meals: 72 to 126 mg/dL (4 to 7 mmol/L) for people with type 1 or type 2 diabetes
- After meals: under 162 mg/dL (under 9 mmol/L) for people with type 1 diabetes and under 153 mg/dL (8.5 mmol/L) for people with type 2 diabetes
Blood sugar levels in diagnosing diabetes
The following table lays out criteria for diagnoses of diabetes and prediabetes.
Table 3. Blood sugar levels in diagnosing diabetes
Plasma glucose test | Normal | Prediabetes | Diabetes |
---|---|---|---|
Random | Below 11.1 mmol/l Below 200 mg/dl | N/A | 11.1 mmol/l or more 200 mg/dl or more |
Fasting | Below 5.5 mmol/l Below 99 mg/dl | 5.6 to 6.9 mmol/l 100 to 125 mg/dl | 7.0 mmol/l or more 126 mg/dl or more |
2 hour post-prandial | Below 7.8 mmol/l Below 140 mg/dl | 7.8 to 11.0 mmol/l 140 to 199 mg/dl | 11.1 mmol/l or more 200 mg/dl or more |
Checking Your Blood Sugar
Blood sugar (blood glucose) monitoring is the main tool you have to check your diabetes control. This check tells you your blood glucose level at any one time.
Keeping a log of your results is vital. When you bring this record to your health care provider, you have a good picture of your body’s response to your diabetes care plan.
People that may benefit from checking blood glucose include those:
- taking insulin
- that are pregnant
- having a hard time controlling blood glucose levels
- having low blood glucose levels
- having low blood glucose levels without the usual warning signs
- have ketones from high blood glucose levels
How Do I Check My Blood Sugar?
- After washing your hands, insert a test strip into your meter.
- Use your lancing device on the side of your fingertip to get a drop of blood.
- Touch and hold the edge of the test strip to the drop of blood, and wait for the result.
- Your blood glucose level will appear on the meter’s display.
Note: All meters are slightly different, so always refer to your user’s manual for specific instructions.
Other tips for checking:
- With some meters, you can also use your forearm, thigh or fleshy part of your hand.
- There are spring-loaded lancing devices that make sticking yourself less painful.
- If you use your fingertip, stick the side of your fingertip by your fingernail to avoid having sore spots on the frequently used part of your finger.
What is normal blood sugar range for diabetics
The American Diabetes Association suggests the following targets for most nonpregnant adults with diabetes. More or less stringent glycemic goals may be appropriate for each individual.
- HbA1C: 7%
- A1C may also be reported as eAG: 154 mg/dL
- Before a meal (preprandial plasma glucose): 80–130 mg/dL (4.4 – 7.2 mmol/L)
- 1-2 hours after beginning of the meal (Postprandial plasma glucose)*: Less than 180 mg/dL (10.0 mmol/L)
*Postprandial glucose may be targeted if A1C goals are not met despite reaching preprandial glucose goals.
Blood sugar test
Blood sugar test, also known as: Blood Sugar, Fasting Blood Sugar (FBS), Fasting Blood Glucose (FBG), Fasting Plasma Glucose (FPG), Blood Glucose, Oral Glucose Tolerance Test (OGTT), Glucose Tolerance Test (GTT), Urine Glucose.
The blood glucose test may be used to:
- Detect high blood glucose (hyperglycemia) and low blood glucose (hypoglycemia)
- Screen for diabetes in people who are at risk before signs and symptoms are apparent; in some cases, there may be no early signs or symptoms of diabetes.
- Screening can therefore be useful in helping to identify it and allowing for treatment before the condition worsens or complications arise.
- Help diagnose diabetes, prediabetes and gestational diabetes
- Monitor glucose levels in people diagnosed with diabetes
A few different testing protocols may be used to evaluate blood glucose levels, depending on the purpose.
Screening and Diagnosis
The following tests may be used for screening and diagnosis of type 1, type 2 or prediabetes. (Gestational diabetes testing is different—see below.) If the initial screening result from one of the tests is abnormal, the test is repeated on another day. The repeat result must also be abnormal to confirm a diagnosis of diabetes.
- Fasting glucose (fasting blood glucose, FBG) – this test measures the level of glucose in the blood after fasting for at least 8 hours.
- 2-hour glucose tolerance test (GTT) – for this test, the person has a fasting glucose test done (see above), then drinks a 75-gram glucose drink. Another blood sample is drawn 2 hours after the glucose drink. This protocol “challenges” the person’s body to process the glucose. Normally, the blood glucose level rises after the drink and stimulates the pancreas to release insulin into the bloodstream. Insulin allows the glucose to be taken up by cells. As time passes, the blood glucose level is expected to decrease again. When a person is unable to produce enough insulin, or if the body’s cells are resistant to its effects (insulin resistance), then less glucose is transported from the blood into cells and the blood glucose level remains high.
- Hemoglobin A1c (also known as A1c, HbA1c, Glycohemoglobin, Glycated Hemoglobin, Glycosylated Hemoglobin) may be used as an alternative to glucose testing for screening and diagnosis. Hemoglobin A1c, is hemoglobin with glucose attached. The A1c test evaluates the average amount of glucose in the blood over the last 2 to 3 months by measuring the percentage of glycated (glycosylated) hemoglobin. Hemoglobin is an oxygen-transporting protein found inside red blood cells (RBCs). There are several types of normal hemoglobin, but the predominant form – about 95-98% – is hemoglobin A. As glucose circulates in the blood, some of it spontaneously binds to hemoglobin A. The higher the level of glucose in the blood, the more glycated hemoglobin is formed. Once the glucose binds to the hemoglobin, it remains there for the life of the red blood cell – normally about 120 days. The predominant form of glycated hemoglobin is referred to as A1c. A1c is produced on a daily basis and slowly cleared from the blood as older red blood cells die and younger red blood cells (with non-glycated hemoglobin) take their place.Hemoglobin A1c test may be used to screen for and diagnose diabetes or risk of developing diabetes. Standards of medical care in diabetes from the American Diabetes Association (ADA) state that diabetes may be diagnosed based on A1c criteria or plasma glucose criteria, either the fasting plasma glucose (FPG) or the 2-hour plasma glucose value after a 75-g oral glucose tolerance test (OGTT).Hemoglobin A1c test is also used to monitor treatment for someone who has been diagnosed with diabetes. It helps to evaluate how well the person’s glucose levels have been controlled by treatment over time. For monitoring purposes, an A1c of less than 7% indicates good glucose control and a lower risk of diabetic complications for the majority of diabetics.However, the American Diabetes Association and the European Association for the Study of Diabetes recommend that the management of glucose control in type 2 diabetes be more “patient-centered.” Data from recent studies have shown that low blood sugar (hypoglycemia) can cause complications and that people with risk of severe hypoglycemia, disease duration, underlying health conditions, established vascular complications, and a limited life expectancy do not necessarily benefit from having a stringent goal of less than 7% for their A1c. It is recommend that people work closely with their healthcare provider to select a goal that reflects each person’s individual health status and that balances risks and benefits.
Sometimes a blood sample may be drawn and glucose measured when a person has not been fasting, for example, when a comprehensive metabolic panel (CMP) is performed. If the result is abnormal, it is typically followed up with a fasting blood glucose test or a GTT.
Glucose blood tests are also used to screen pregnant women for gestational diabetes between their 24th and 28th week of pregnancy. The American Diabetes Association and the U.S. Preventive Services Task Force recommend that pregnant women not previously known to have diabetes be screened and diagnosed, using either a one-step or two-step approach. The American College of Obstetricians and Gynecologists recommends the two-step approach.
- One-step 2-hour oral glucose tolerance test (OGTT). After a fasting glucose level is measured, a woman is given a 75-gram dose of glucose to drink and her glucose levels are measured at 1 hour and 2 hours after the dose. Only one of the values needs to be above a cutoff value for diagnosis.
- Two-step
- Perform a glucose challenge test as a screen: a woman is given a 50-gram glucose dose to drink and her blood glucose level is measured after 1 hour.
- If the challenge test is abnormal, perform a 3-hour oral glucose tolerance test. After a woman’s fasting glucose level is measured, she is given a 100-gram glucose dose and her glucose is measured at timed intervals. If at least two of the glucose levels at fasting, 1 hour, 2 hour, or 3 hour are above a certain level, then a diagnosis of gestational diabetes is made.
Glucose testing is also used to test women who were diagnosed with gestational diabetes 6-12 weeks after they have delivered their baby to detect persistent diabetes.
Table 4. Gestational Diabetes One-Step Approach (as one option recommended by the American Diabetes Association)
Time of sample collection | glucose level |
---|---|
Fasting | Equal to or greater than 92 mg/dL (5.1 mmol/L) |
1 hour | Equal to or greater than 180 mg/dL (10.0 mmol/L) |
2 hour | Equal to or greater than 153 mg/dL (8.5 mmol/L) |
Note: Samples drawn fasting and then 1 hour and 2 hours after a 75-gram glucose drink. Diagnosis of gestational diabetes mellitus is made when any of the values exceed the limit.
[Source 5]Table 5. Gestational Diabetes Two-Step Approach (as currently recommended by American College of Obstetricians and Gynecologists and as one option from the American Diabetes Association):
Step One
Glucose Level | Indication |
---|---|
Less than 140* mg/dL (7.8 mmol/L) | Normal screen |
140* mg/dL (7.8 mmol/L) and over | Abnormal, needs OGTT (see Step two below) |
Note: Step One: Glucose Challenge Screen. Sample drawn 1 hour after a 50-gram glucose drink.
*Some experts recommend a cutoff of 130 mg/dL (7.2 mmol/L) because that identifies 90% of women with gestational diabetes, compared to 80% identified using the threshold of 140 mg/dL (7.8 mmol/L). ACOG recommends a lower threshold of 135 mg/dL (7.5 mmol/L) in high-risk ethnic groups with higher prevalence of gestational diabetes.
[Source 5]Table 6. Gestational Diabetes Two-Step Approach (as currently recommended by American College of Obstetricians and Gynecologists and as one option from the American Diabetes Association):
Step Two
Time of sample collection | target levels** |
---|---|
Fasting (prior to glucose load) | 95 mg/dL (5.3 mmol/L) |
1 hour after glucose load | 180 mg/dL (10.0 mmol/L) |
2 hours after glucose load | 155 mg/dL (8.6 mmol/L) |
3 hours after glucose load | 140 mg/dL (7.8 mmol/L) |
Note: Step Two: Diagnostic OGTT. Samples drawn at fasting and then 1, 2 and 3 hours after a 100-gram glucose drink. If two or more values meet or exceed the target level, gestational diabetes is diagnosed. One of two sets of criteria may be used to establish a diagnosis.
**Some labs may use different numbers.
[Source 5]Monitoring
Diabetics must monitor their own blood glucose levels, often several times a day, to determine how far above or below normal their glucose is and to determine what oral medications or insulin(s) they may need. This is usually done by placing a drop of blood from a skin prick onto a glucose strip and then inserting the strip into a glucose meter, a small machine that provides a digital readout of the blood glucose level.
Urine Glucose
Urine glucose is one of the substances tested when a urinalysis is performed. A urinalysis may be done routinely as part of a physical or prenatal checkup. The health practitioner may follow up an elevated urine glucose test with blood glucose testing. Urine glucose testing is a screening tool, but it is not sensitive enough for diagnosis or monitoring.
Low to undetectable urine glucose results are considered normal. Any condition that raises blood glucose such as diabetes or the other conditions listed above also has the potential to elevate the concentration of glucose in the urine.
Increased urine glucose may be seen with medications, such as estrogens and chloral hydrate, and with some forms of kidney disease. Some people naturally leak glucose in their urine when blood levels are normal. Some medications used to treat diabetes work by increasing the elimination of glucose in the urine.
Other tests, such as diabetes autoantibodies, insulin, and C-peptide, may sometimes be performed along with these tests to help determine the cause of abnormal glucose levels, to distinguish between type 1 and type 2 diabetes, and to evaluate insulin production.
Random plasma glucose test
A blood sample for a random plasma glucose test can be taken at any time. This doesn’t require as much planning and is therefore used in the diagnosis of type 1 diabetes when time is of the essence.
Fasting plasma glucose test
A fasting plasma glucose test is taken after at least eight hours of fasting and is therefore usually taken in the morning.
- The NICE guidelines regard a fasting plasma glucose result of 109.8–124.2 mg/dL (6.1 to 6.9 mmol/l) as putting someone at higher risk of developing type 2 diabetes, particularly when accompanied by other risk factors for type 2 diabetes.
Oral Glucose Tolerance Test (OGTT)
An oral glucose tolerance test involves taking a first taking a fasting sample of blood and then taking a very sweet drink containing 75g of glucose.
After having this drink you need to stay at rest until a further blood sample is taken after 2 hours.
The test is used to determine whether the body has difficulty metabolizing intake of sugar/carbohydrate.
The patient is asked to take a glucose drink and their blood glucose level is measured before and at intervals after the sugary drink is taken.
Why is an oral glucose tolerance test done?
This can be a useful test in helping to diagnose:
- Pre-diabetes
- Gestational diabetes in pregnant women
- Insulin resistance
- Reactive hypoglycemia
How is the OGTT test performed?
Before the test you will be asked not to eat, or drink certain fluids, for up to 8 to 12 hours before the test.
You may be asked to not take certain medications in the lead up to the test, but only if these would affect the test results.
For the test itself, you will first have blood taken to measure your blood glucose level before the test. The next stage is to take a very sweet tasting, glucose drink.
Further blood samples will then be taken either at regular intervals of say 30 or 60 minutes or a single test after 2 hours. The test could take up to 3 hours.
Between blood tests you will need to wait so it’s best to have some reading material, or something else to keep you occupied, with you.
What should the OGTT results be?
People without diabetes
- Fasting value (before test): under 99 mg/dL (under 5.5 mmol/L)
- At 2 hours: under 140.4 mg/dL (under 7.8 mmol/L)
People with impaired glucose tolerance (IGT)
- Fasting value (before test): 100 to 125 mg/dL (5.6 to 6.9 mmol/L)
- At 2 hours: 140 to 199 mg/dL (7.8 to 11.1 mmol/L)
Diabetic levels
- Fasting value (before test): over 126 mg/dL (over 7.0 mmol/L)
- At 2 hours: over 200 mg/dL (over 11.1 mmol/L)
HbA1c test for diabetes diagnosis
An HbA1c test does not directly measure the level of blood glucose, however, the result of the test is influenced by how high or low your blood glucose levels have tended to be over a period of 2 to 3 months.
Indications of diabetes or prediabetes are given under the following conditions:
- Normal: Below 42 mmol/mol (6.0%)
- Prediabetes: 42 to 47 mmol/mol (6.0 to 6.4%)
- Diabetes: 48 mmol/mol (6.5% or over)
When is random plasma glucose test ordered?
Several health organizations, including the American Diabetes Association and the U. S. Preventive Services Task Force, recommend diabetes screening when a person is age 45 or older or when a person of any age has risk factors. Examples of risk factors include:
- Overweight, obese, or physically inactive
- A close (first degree) relative with diabetes
- A woman who delivered a baby weighing more than 9 pounds or with a history of gestational diabetes
- A woman with polycystic ovarian syndrome
- High-risk race or ethnicity such as African American, Latino, Native American, Asian American, Pacific Islander
- High blood pressure (hypertension) or taking medication for high blood pressure
- Low HDL cholesterol level (less than 35 mg/dL or 0.90 mmol/L) and/or a high triglyceride level (more than 250 mg/dL or 2.82 mmol/L)
- A1c equal to or above 5.7%
- Prediabetes identified by previous testing
- History of cardiovascular disease (CVD)
If the screening test result is within normal limits, the American Diabetes Association recommends retesting within 3 years, while the U. S. Preventive Services Task Force recommends yearly testing. People with prediabetes may be monitored with annual testing.
A blood glucose test may also be ordered when someone has signs and symptoms of high blood glucose (hyperglycemia), such as:
- Increased thirst, usually with frequent urination
- Fatigue
- Blurred vision
- Slow-healing wounds or infections.
Some other diseases and conditions that can result in an elevated blood glucose level (hyperglycemia) include:
- Acromegaly
- Acute stress (response to trauma, heart attack, and stroke for instance)
- Chronic kidney disease
- Cushing syndrome
- Excessive consumption of food
- Hyperthyroidism
- Pancreatic cancer
- Pancreatitis
Extreme stress can cause a temporary rise in blood glucose. This can be a result of, for example, trauma, surgery, heart attack or stroke.
Drugs, including corticosteroids, tricyclic antidepressants, diuretics, epinephrine, estrogens (birth control pills and hormone replacement), lithium, phenytoin, and salicylates, can increase glucose levels.
or symptoms of low blood glucose (hypoglycemia), such as:
- Sweating
- Hunger
- Trembling
- Anxiety
- Confusion
- Blurred vision
A low blood glucose level (hypoglycemia) may be seen with:
- Adrenal insufficiency
- Drinking excessive alcohol
- Severe liver disease
- Hypopituitarism
- Hypothyroidism
- Severe infections
- Severe heart failure
- Chronic kidney (renal) failure
- Insulin overdose
- Tumors that produce insulin (insulinomas)
- Starvation
- Deliberate use of glucose-lowering products
- Drugs such as acetaminophen and anabolic steroids can decrease levels.
Diabetics are often required to self-check their glucose, up to several times a day, to monitor glucose levels and to determine treatment options as prescribed by their health practitioner. The healthcare provider may order blood glucose levels periodically in conjunction with other tests such as A1c to monitor glucose control over time.
Pregnant women are usually screened for gestational diabetes between their 24th and 28th week of pregnancy, unless they have early symptoms or have had gestational diabetes with a previous pregnancy. A woman may be tested earlier in her pregnancy if she is at risk of type 2 diabetes (overt diabetes), says the American Diabetes Association. When a woman has type 1, type 2 or gestational diabetes, her health practitioner will usually order glucose levels throughout the rest of her pregnancy and after delivery to monitor her condition.
Can I test myself at home for blood glucose levels?
If you are not diabetic or prediabetic, there is usually no reason to test glucose levels at home. Screening done as part of your regular physical should be sufficient.
If you have been diagnosed with diabetes or gestational diabetes, however, your health practitioner or diabetes educator will recommend a home glucose monitor (glucometer, or one of the newer methods that use very tiny amounts of blood or tests the interstitial fluid — the fluid between your cells — for glucose). You will be given guidelines for how high or low your blood sugar should be at different times of the day. By checking your glucose regularly, you can see if the diet and medication schedule you are following is working properly for you.
Blood Sugar Levels During Pregnancy
Blood glucose control is one of the most important factors during pregnancy. Tight blood glucose control, helps to ensure the best chance of a successful pregnancy.
Diabetes control is important for people who have diabetes going into their pregnancy as well as people who develop diabetes during their pregnancy (gestational diabetes).
What is gestational diabetes?
It has been reported that on average 2% to 4% of women develop temporary diabetes also known as gestational diabetes.
This happens because they are unable to produce an increased amount of insulin to overcome the resistance levels.
In gestational diabetes there is not normally any show of external symptoms normally recognised as characteristic of the disease for example excessive thirst, tiredness and increased urination.
Blood sugar control during pregnancy
Good blood glucose control reduces the risks of complications developing for the mother and baby.
The target HbA1c for mothers before and during pregnancy is 6.1% (or 43 mmol/mol) 6.
People with diabetes before their pregnancy will be advised to keep excellent control of their blood sugar before and throughout the pregnancy.
The first eight weeks of the pregnancy are a critical period and so it is highly recommended that strong control is achieved prior to becoming pregnant wherever possible.
Mothers who develop gestational diabetes will be treated initially with diet and exercise but may be put onto oral hypoglycaemics (tablets) or insulin injections if blood sugar levels remain high.
Diabetes management
To help you to meet the challenging blood glucose targets, you will be expected to test your blood glucose before each meal and 1 hour after eating.
People taking insulin for their diabetes will also need to test before bed each night.
You will have blood tests performed at various intervals during your pregnancy to check your diabetes is under good control.
You should expect to receive a high standard of care from your health team throughout your pregnancy and should have the opportunity to ask any questions you may have about achieving your health targets.
How does diabetes affect the baby?
There have been reports that diabetes during pregnancy brings increased chances of having a bigger babies and birth defects.
Infant mortality and birth defects
There is a slight increase in the risk of infant mortality or birth defects in baby’s of mother with diabetes than without, however preconception care can reduce this risk by ensuring the mother is as healthy as possible before and through out pregnancy.
In addition to this if a woman has diabetes before pregnancy, diabetes related complications can worsen; this includes things like hypertension, kidney disease, nerve damage and retinopathy which is a form of diabetic eye disease.
Excess insulin
The baby of a woman with diabetes often produces excess insulin in response to high blood glucose levels within the body of the mother.
In type 1 diabetes no significant extra insulin will be produced by your body so you may see your insulin requirements increased. Your health team should be able to advise with the best way to manage your diabetes.
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- https://www.nice.org.uk/guidance/ng28[↩][↩]
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- Diabetes in pregnancy overview. https://pathways.nice.org.uk/pathways/diabetes-in-pregnancy[↩]