Alternative Names low blood sugar, low blood glucose
Definition Hypoglycaemia is the condition that occurs when blood sugar, or glucose, levels drop below normal.
What is going on in the body? Blood sugar levels drop when people don't eat for a long time, or when they have complications of diabetes and other diseases. The blood glucose level is affected by the hormones insulin and glucagon. An imbalance of these hormones can cause blood sugar levels to fall too low. When the blood sugar falls too low, hypoglycaemia develops.
What are the signs and symptoms of the condition? When blood sugar drops and hypoglycaemia develops, most people will begin feeling weak, drowsy, excessively hungry, and dizzy. A person may feel confused or irritable. The person may appear pale, may tremble, or feel cold and clammy. A rapid heartbeat may also be felt. In severe cases, usually associated with diabetes, a person can lose consciousness and lapse into a coma.
What are the causes and risks of the condition? Hypoglycaemia usually occurs in people with diabetes. When people have diabetes, the pancreas does not make enough insulin or the insulin made is not effective. Blood sugar rises and builds up in the blood. People with diabetes take insulin or oral medications to keep their blood sugar down. If a person with diabetes takes too much medication, misses meals, or doesn't eat enough food, the person can become hypoglycaemic.
Rarely, hypoglycaemia can occur in people who do not have diabetes. Hypoglycaemia can occur in early pregnancy. People can also become hypoglycaemic if they fast for a long time or exercise for an extended period. People taking certain medications, such as beta-blockers or aspirin, may become hypoglycaemic more easily. Sometimes people who are alcoholics or binge drinkers can become hypoglycaemic.
What can be done to prevent the condition? People with diabetes prevent hypoglycaemia by frequently monitoring blood glucose levels and recognising early symptoms of hypoglycaemia. People who have diabetes can prevent hypoglycaemia by keeping their blood sugar levels within their recommended range. They are trained to recognise when their blood sugar levels are dropping. They can quickly eat or drink something with sugar or take glucose tablets to prevent hypoglycaemia from developing. Other people who have hypoglycaemia can learn to eat and exercise in a way that does not cause their blood sugar to drop too low.
How is the condition diagnosed? Hypoglycaemia is diagnosed when a person complains of symptoms. Blood glucose levels are then measured. If the blood glucose levels are 2.5 mmol/L (millimoles per litre) or less in women or 3.0 mmol/L or less in men, hypoglycaemia is present. Finally, if the symptoms go away upon eating sugar or drinking a beverage with sugar, then the person probably has hypoglycaemia.
What are the long-term effects of the condition? Repeated episodes of hypoglycaemia are now thought to cause mild forms of brain damage that may be irreversible. Rarely, severe hypoglycaemia can cause a coma or death.
What are the risks to others? There are no risks to others. This condition is not contagious.
What are the treatments for the condition? The treatment for hypoglycaemia is control of blood sugar levels. People with diabetes learn the early warning symptoms and quickly eat or drink a sugary substance. The same treatment works for people without diabetes who have hypoglycaemia. Usually all people with hypoglycaemia are advised to follow a healthy eating plan with a variety of foods eaten at regular intervals throughout the day.
What are the side effects of the treatments? Too much sugar can cause the level of blood sugar to go too high. This is rarely a problem, except in people with severe diabetes.
What happens after treatment for the condition? People begin to feel better very quickly after they bring up their blood sugar to normal ranges. The uncomfortable physical symptoms soon disappear after eating or drinking something with sugar.
How is the condition monitored? People who become hypoglycaemic easily, whether they have diabetes or not, learn to monitor their symptoms. The best way to avoid the uncomfortable, and sometimes dangerous, symptoms of hypoglycaemia is to prevent the problem in the first place. People with diabetes who are prone to low blood sugar learn to monitor levels frequently to keep blood sugar within normal ranges.
Author: Terry Mason, MPH Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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