Causes of Hypoglycaemia
The Rapid Investigation of Low Blood Sugar is Essential
Although more commonly seen in diabetics, hypoglycaemia can occur for other reasons. These need to be investigated and treated quickly.
Hypoglycaemia means that the glucose in the blood has dropped to a level that may cause harm if prolonged. This level is around 2.5mmols/litre in most people.
The most frequent reason for this is seen in diabetics due to the failure to adequately match insulin dose (or diabetic tablets) with food intake and energy expenditure – in effect, an insulin overdose. However it can occur in non-diabetics for a variety of reasons. As the effects of low blood glucose can be serious, rapid attention to the problem is paramount.
Control of Blood Glucose Level
Blood glucose is a prime source of energy for the muscles and organs of the body. Whereas many tissues can also utilise fat for their energy needs the brain can only use glucose, a fact that has considerable bearing on the consequences of hypoglycaemia.
The hormone insulin removes glucose from the blood and transports it into the muscles and the liver where it is stored. Glucagon, also a hormone, has the opposite effect and removes glucose from storage to enter the circulation.
Clearly fine control of these two hormones, and incidentally many other factors, is needed to maintain blood glucose at appropriate levels.
Causes of Hypoglycaemia
- Reactive hypoglycaemia: probably caused by an overproduction of insulin following a high carbohydrate meal. The left over insulin mops up too much glucose from the blood.
- Tumour: pancreatic tumours, which are usually benign, can secrete large amounts of insulin
- Addison’s disease; a disease of the adrenal glands. Some of the hormones secreted by the adrenal have a marked effect on glucose metabolism
- Reduced liver function; dysfunction of the liver can disturb the control of glucose storage.
- Poor functioning pituitary gland.
- Partial gastrectomy: when the stomach is made smaller food enters the small intestine quicker than it should. This stimulates overproduction of insulin leading to a reactive hypoglycaemia.
- Cancer: many cancers can have a marked effect on the body’s energy metabolism.
- Fasting or malnutrition
- Excess alcohol
Signs and Symptoms of Hypoglycaemia
Depending on the individual and degree of hypoglycaemia, some or all of those listed below may be experienced.
- Pallor, trembling, perspiration
- Hunger, agitation rapid heart beat
- Feeling weak, irritability, fatigue
- Poor concentration, blurred vision
- Convulsions, loss of consciousness.
The last two – convulsions and loss of consciousness suggest that the brain is becoming impaired through lack of glucose. As indicated earlier the brain has no other energy supply to fall back on so permanent damage can occur unless action is taken rapidly.
Treatment
The important first step is to make sure your signs and symptoms really are due to low blood sugar. The only way to do this is to get it measured by your physician. If hypoglycaemia is occurring the cause needs be found and treated.
Reactive hypoglycaemia is treated by diet. The trick is to avoid large surges of insulin. This is best done by avoiding refined sugars and eating more complex carbohydrates. Essentially these are carbohydrates that require effort by the body to digest and assimilate ensuring slower entry of glucose into the blood stream. Wholemeal breads, particularly with grains in, whole fruits rather than smoothies are best. It’s also important to eat plenty of fresh vegetables as the presence of these in the gut will help ensure slower absorption of glucose.
This article is intended for information only. If you think you might be experiencing low blood glucose you should visit a health professional.
Reference
Medicine. Eds. Souhami and Moxham. Churchill Livingstone 1994
