What is Glucose in Blood Test? What is High and Low Glucose Level? Causes & Treatment?
- Health Garden
- Mar 30, 2024
- 4 min read
Updated: Jul 25, 2024
Glucose in blood test is a test that shows the level of glucose in the blood.
Glucose is the building block of carbohydrates. Foods containing carbohydrates are broken down in the digestive tract and converted into glucose. Glucose is absorbed from the intestines and mixes with the blood. For this reason, it is also called "blood sugar". Glucose carried by blood is used as an energy source in all tissues and organs. If there is more glucose than necessary in the body, it is stored in our liver and muscles to be used when needed.
Insulin and glucagon hormones in the pancreas regulate blood sugar levels. Insulin ensures the passage of sugar into cells, preventing it from accumulating excessive amounts in the blood. Glucagon, on the other hand, ensures that the stored glucose is mixed back into the blood when the blood sugar level drops.
Glucose in blood test is often used to help diagnose and monitor diabetes.
Other names are blood sugar, self-monitoring of blood glucose (SMBG), fasting plasma glucose (FPG), fasting blood sugar (FBS), fasting blood glucose (FBG), random blood sugar, glucose challenge test, oral glucose tolerance test (OGTT).
What is A Normal Glucose Level in Blood Test ?
According to international diagnostic criteria, fasting blood glucose value in healthy individuals is expected to be between 70-100 mg/dl, and postprandial blood glucose value is expected to be below 140 mg/dl. In some healthy individuals, a fasting glucose value between 50 and 70 mg/dL may be normal. Hunger is 8 hours after the last feeding, satiety is the first 2 hours after feeding. These times are average values, please give priority to your doctor's advice. Reference ranges may vary between laboratories. The reference value of the laboratory where the test was performed should be taken into account.
What is High Glucose Level in Blood Test?
In a blood test, high blood sugar is defined as over 100 when fasting and over 140 when fed.
High glucose in the blood is called hyperglycemia.
If the fasting blood sugar level is between 100 and 125 mg/dL, this is usually indicative of prediabetes. Fasting blood sugar above 126 mg/dl and postprandial blood sugar above 200 mg/dl are usually signs of diabetes. In either case, the doctor will usually order a hemoglobin A1c (HbA1c) test before diagnosing prediabetes or diabetes. HbA1c shows the average blood sugar over several months.
If the glucose value is high in the blood test, it means that not enough insulin is secreted or insulin is insufficient.
Untreated high glucose levels can damage nerves, blood vessels, tissues and organs.
What Causes High Glucose Level in Blood Test?
Possible causes of high glucose include
Diabetes
Hyperthyroidism
Pancreatic disorders
Operation
Stress
Use of steroid group drugs
Endocrinological (hormonal) diseases
Cushing's syndrome
High Glucose Symptoms
Possible symptoms that may occur with high glucose include:
Frequent urination during the day and especially at night
Excessive thirst, drinking water too often
Feeling hungry frequently
Dry mouth
Acetone-like odor in the mouth
Fatigue
Delayed healing of wounds
Weight loss for unknown reason
Burning sensation in feet
Dry skin
Blurred vision
Recurring infections
How to Treat High Glucose Level?
Treatment of high glucose is based on the underlying cause. If the diagnosis is diabetes, insulin regulating drugs or insulin injection treatment may be applied. Doing the following under the supervision of a healthcare professional may help regulate blood sugar:
Take advantage of foods with low glycemic index
Limit sugar consumption
Consume foods containing magnesium
Choose foods containing dietary fiber
Stay away from stress
Increase water consumption
Pay attention to your sleep quality
Limit caffeine and alcohol consumption
Exercise regularly
What is Low Glucose Level in Blood Test?
Low glucose in a blood test is a value below 70 mg/dl. However, for some people, 50 to 70 mg/dl may be normal. Glucose levels below 50 mg/dl can be dangerous.
Low blood sugar level is called hypoglycemia.
Low blood sugar levels are common in people with type 1 diabetes and in people with type 2 diabetes who take certain diabetes medications.
What Causes Low Glucose Level in Blood Test?
If you have diabetes, lower than normal glucose levels may be caused by:
Side effects from certain diabetes medicines
Not eating enough, especially after taking diabetes medicine
Being more physically active than usual
If you don't have diabetes, low blood glucose levels may be a sign of:
Liver disease
Kidney disease
Underactive adrenal, pituitary, or thyroid gland (hypothyroidism)
Alcohol use disorder
Weight loss after weight loss surgery
Low Glucose Symptoms
Possible symptoms that may occur with low glucose include:
Hunger
Fatigue
Feeling dizzy, confused, or irritable
Headache
A fast heartbeat or arrhythmia
Having trouble seeing or speaking
Sweating
Anxiety
How to Treat Low Glucose Level?
Low glucose treatment is primarily aimed at increasing the sugar level in the blood. This can be achieved by eating or by injection. Then, the underlying cause of low glucose should be investigated and treatment should be adjusted. Adopting a healthy diet and lifestyle under the supervision of a healthcare professional can help regulate blood sugar levels.