Skip to content

Low blood sugar: causes, symptoms, tests, treatments and preventions

In a normal human body, blood sugar is kept constant at about 80-150mg/dL and is a major source of energy sent to each part of our body. Low blood sugar, or hypoglycemia, refers to a condition in which the amount of glucose supplied to body organs decreases and various symptoms are caused by a decrease in blood sugar below the normal level due to various causes.


The most common cause of low blood sugar is insulin or oral diabetes medications used to treat diabetes. Low blood sugar can occur if sulfone urea or insulin is administered in excess of oral diabetes medications. Decreased diet or increased exercise while using these medications can lead to low blood sugar. Diabetics are at an increased risk of low blood sugar even if they drink alcohol.

Even people without diabetes can develop low blood sugar when they have liver, kidney, or heart disease or severe conditions such as sepsis or malnutrition. Low blood sugar can also occur when the amount of insulin in the body is abnormally increased due to various diseases such as pancreatic insulin-secreting tumors and autoimmune diseases against insulin. Postprandial low blood sugar disease, in which low blood sugar occurs only after meals, can occur after gastrectomy or due to insulin resistance.


When low blood sugar occurs, glucose supplied to the brain and nervous system becomes insufficient, and the body’s autonomic nervous system is activated by feeling a lack of energy. As a result, dizziness and fatigue may occur. When it gets worse, epileptic seizures and loss of consciousness can occur, and even death. In addition, to overcome low blood sugar, the sympathetic nerve is elevated, which leads to an increase in blood pressure, heart palpitations, and trembling, and the parasympathetic nerve to compensate for this can cause cold sweat and feelings of hunger.


In diabetics, it is important to identify the type of diabetic medications being administered and to determine what circumstances may cause low blood sugar. In people without diabetes, tests are done to prove hypoglycemia and to determine its cause. When fasting or low blood sugar symptoms appear, blood tests to measure insulin and C-peptide are performed along with blood sugar measurements. If necessary, a test that induces low blood sugar may be performed while fasting for up to 72 hours after hospitalization.


If hypoglycemia is suspected, conscious patients should eat foods containing sugar as soon as possible. Unconscious patients should be immediately sent to the emergency room to receive glucose as fluid. Diabetes patients should eat foods containing 15 mg of carbohydrates. For example, half a glass of juice (150 ml), 3-5 candies, and glucose candies. After that, appropriate treatment is required depending on the cause. If a diabetic suffers from repeated low blood sugar, it is necessary to adjust diabetes medications or dietary habits. If a patient has a pancreatic insulin-secreting tumor, it should be treated surgically.

Progress and complications

If left untreated, hypoglycemia is a serious disease that can cause brain damage and life-threatening in a short period of time. Therefore, when hypoglycemia is diagnosed, the cause should be identified and appropriate treatment should be performed. Diabetes patients should be cautious because repetitive exposure to low blood sugar may lead to low blood sugar insensitivity, which is less likely to feel symptoms of low blood sugar.


It is important for diabetics to adhere to the usage and dosage of their diabetes medication and to eat regularly. In addition, if the patient is exercising more than usual, it is helpful to measure blood sugar before and after exercise. It is recommended to exercise 30 minutes to 1 hour after meals, avoiding fasting as much as possible. When going out or exercising, bring a snack in case of low blood sugar.

2 thoughts on “Low blood sugar: causes, symptoms, tests, treatments and preventions”

Leave a comment