The NIDDK on Hypoglycemia
What Are the Symptoms of Hypoglycemia?
A person with hypoglycemia may feel weak, drowsy, confused, hungry, and dizzy. Paleness, headache, irritability, trembling, sweating, rapid heart beat, and a cold, clammy feeling are also signs of low blood sugar. In severe cases, a person can lose consciousness and even lapse into a coma.
The symptoms associated with hypoglycemia are sometimes mistaken for symptoms caused by conditions not related to blood sugar. For example, unusual stress and anxiety can cause excess production of catecholamines, resulting in symptoms similar to those caused by hypoglycemia but having no relation to blood sugar levels.
Hypoglycemia in Diabetes
The most common cause of hypoglycemia is as a complication of diabetes. Diabetes occurs when the body cannot use glucose for fuel because either the pancreas is not able to make enough insulin or the insulin that is available is not effective. As a result, glucose builds up in the blood instead of getting into body cells.
The aim of treatment in diabetes is to lower high blood sugar levels. To do this, people with diabetes may use insulin or oral drugs, depending on the type of diabetes they have or the severity of their condition. Hypoglycemia occurs most often in people who use insulin to lower their blood sugar. All people with type 1 diabetes and some people with type 2 diabetes use insulin. People with type 2 diabetes who take oral drugs called sulfonylureas are also vulnerable to low blood sugar episodes.
Conditions that can lead to hypoglycemia in people with diabetes include taking too much medication, missing or delaying a meal, eating too little food for the amount of insulin taken, exercising too strenuously, drinking too much alcohol, or any combination of these factors. People who have diabetes often refer to hypoglycemia as an "insulin reaction."
Managing Hypoglycemia in Diabetes
People with diabetes should consult their health care providers for individual guidelines on target blood sugar ranges that are best for them. The lowest safe blood sugar level for an individual varies, depending on the person's age, medical condition, and ability to sense hypoglycemic symptoms. A target range that is safe for a young adult with no diabetes complications, for example, may be too low for a young child or an older person who may have other medical problems.