What Is Low Blood Sugar?

Hypoglycemia means that the fasting blood glucose concentration of an adult is below 2.8mmol / L. Low blood sugar can be diagnosed if the blood glucose level of diabetics is 3.9 mmol / L. Hypoglycemia is a group of syndromes caused by a variety of etiologies with venous plasma glucose (glycemic) concentration being too low and clinically characterized by sympathetic nerve excitation and brain cell hypoxia. Symptoms of hypoglycemia are usually sweating, hunger, palpitation, trembling, pale, etc. In severe cases, there may also be inattention, restlessness, irritability and even coma.

Basic Information

English name

hypoglycemia

Visiting department

Endocrinology

Multiple groups

Diabetics

Common symptoms

Sweating, hunger, palpitation, trembling, pale

Causes of hypoglycemia

Recurring fasting hypoglycemia clinically indicates organic disease; reactive hypoglycemia caused by meals is more common in functional diseases.

Fasting hypoglycemia

(1) Excessive secretion of endogenous insulin: insulinoma and autoimmune hypoglycemia are common.

(2) medicinal properties: such as injection of insulin, sulfonylurea hypoglycemic drugs, salicylic acid, drinking, etc.

(3) Severe diseases: such as liver failure, heart failure, kidney failure, malnutrition, etc.

(4) Lack of insulin antagonist hormones: such as glucagon, growth hormone, cortisol, etc.

(5) Extrapancreatic tumor.

2. Postprandial (reactive) hypoglycemia

(1) Congenital deficiency of carbohydrate metabolism enzymes: such as hereditary fructose intolerance.

(2) Idiopathic reactive hypoglycemia.

(3) Nourishing hypoglycemia (including dumping syndrome).

(4) Functional hypoglycemia.

(5) Hypoglycemia in the late meals of type 2 diabetes.

Clinical manifestations of hypoglycemia

Hypoglycemia is onset, the time and frequency of which varies with the cause, and the symptoms can vary. The clinical manifestations can be summarized as the following two aspects.

1. The manifestation of autonomic (sympathetic) nerve overexcitation

During the onset of hypoglycemia, due to the release of adrenaline and norepinephrine by sympathetic nerves and adrenal medulla, the clinical manifestations are sweating, hunger, palpitation, tremor, pale, etc.

2. Performance of brain dysfunction

It is a series of manifestations of dysfunction when the brain lacks sufficient glucose supply. Initial manifestations include mental symptoms such as lack of concentration, sluggish thinking and speech, dizziness, drowsiness, restlessness, irritability, and strange behavior. In severe cases, convulsions, coma, and even death.

Hypoglycemia check

1. Blood glucose: The fasting blood glucose concentration of adults is lower than 2.8mmol / L, and the blood glucose value of diabetic patients is lower than 3.9mmol / L.

2. Plasma insulin measurement: During the onset of hypoglycemia, such as elevated plasma insulin and C-peptide levels, it is suggested that hypoglycemia is caused by excessive insulin secretion.

3. 48-72 hours starvation test: A small number of patients with undetected hypoglycemia or non-seizure and highly suspected insulinoma should be performed under close observation. Blood samples were taken before the blood glucose, insulin, and C-peptide were measured, and then every 6 hours.

Hypoglycemia diagnosis

According to the typical manifestations of hypoglycemia (Whipple triad): symptoms of hypoglycemia; blood glucose is less than 2.8mmol / L at the time of onset; A small number of patients whose fasting blood glucose is not significantly reduced or in a non-seizure phase should be tested for fasting or hypoglycemia after absorption multiple times. If necessary, a 48-72 hour starvation test is used.

Differential diagnosis of hypoglycemia

Hypoglycemia can sometimes be misdiagnosed as a mental illness, a neurological disorder (epilepsy, transient ischemic attack), or a cerebrovascular accident.

1. Identification of the cause of hypoglycemia: sulfonylureas, excessive insulin use, insulinoma, etc.

2. Identification of sympathetic nerve excitation performance: hyperthyroidism, pheochromocytoma, autonomic dysfunction, diabetic autonomic neuropathy, menopausal syndrome, etc.

3. Identification of psycho-neuro-behavioral abnormalities: psychosis, cerebrovascular accident, diabetic ketoacidosis coma, hyperglycemia and hypertonic state, etc.

Hypoglycemia treatment

Treatment includes two aspects: one is to relieve the symptoms of hypoglycemia, and the other is to correct various underlying causes of hypoglycemia. For mild to moderate hypoglycemia, oral sugar water, sugary drinks, or eating sweets, biscuits, bread, steamed buns, etc. can alleviate. For drug-induced hypoglycemia, relevant drugs should be stopped in a timely manner. In severe cases and patients with suspected hypoglycemic coma, capillary blood glucose should be measured in time, even without blood glucose results, and 40% to 60ml of 50% glucose should be given in time, followed by intravenous infusion of 5% to 10% glucose. If you are unconscious, do not feed to avoid suffocation of the respiratory tract.

Hypoglycemia prevention

Diabetic patients, especially elderly patients with cardiovascular and cerebrovascular diseases, should pay attention to prevent the occurrence of hypoglycemia.

1. Establish appropriate individualized glycemic control goals.

2. Education for diabetes: including education for patients' families, identification of hypoglycemia, understanding of the pharmacokinetics of drugs used by patients, self-help methods, etc.

3. Fully understand the risk factors that cause hypoglycemia: regular quantitative meals, if the amount of meals is reduced, the drug dose should be reduced accordingly; additional carbohydrate intake should be added before exercise; alcohol can directly cause hypoglycemia, avoid alcoholism and fasting Drinking.

4. Adjust the hypoglycemic regimen: rational use of insulin or insulin secretagogues.

5. Regularly monitor blood glucose, especially when blood glucose fluctuations, environmental, sports and other factors change.