Controlling Blood Glucose - Hypoglycaemia
The clinical term for a low blood glucose level is hypoglycaemia.
In wake of the DCCT and UKPDS, people with diabetes are being advised to tighten up control of blood glucose levels, in order to reduce the risk of developing complications in the long term. However, the downside to this is an increased risk of hypoglycaemia.
Hypoglycaemia is more common among people with Type 1 diabetes, who may have up to one or two episodes of mild hypoglycaemia per week. It is less common, but still possible, among those with Type 2 diabetes.
Symptoms of hypoglycaemia
Symptoms of mild hypoglycaemia vary from person to person. Early recognition and treatment can avert problems so learn to recognise your own symptoms. Tell your family and friends what signs to look out for.
Symptoms may include some of the following:
Hunger
Sweating
Dizziness
Headache
Light-headedness
Irritability
Shakiness
Clammy skin
Loss of co-ordination
Blurred vision
Nausea
Confusion
Nightmares
Crying out during sleep
Heart palpitations or rapid heart rate
Tingling or numbness in the lips or tongue
Severe hypoglycaemia
If mild hypoglycaemia progresses and the blood glucose level continues to drop, the lack of glucose may impair brain function, causing delirium, seizures (fits*) or loss of consciousness.
Hypoglycaemia unawareness
Some people have difficulty recognizing that their blood glucose level is falling; this is known as 'hypoglycaemia unawareness'. It is more common in people who suffer from frequent hypoglycaemia and those who have had diabetes for many years. It is not always a permanent problem - by running blood glucose levels a little higher than usual and avoiding hypos for a while, early warning signs can sometimes be regained.
If you are unable to detect mild hypoglycaemia from symptoms alone, you should:
Increase the number of times you test your blood glucose each day
Consider snacking more often or eating more regular meals
Always test your blood glucose level before driving or using potentially dangerous equipment
Discuss the situation with your diabetes healthcare team
Educate your friends, relatives, and co-workers about hypoglycaemia so that they can recognise the condition
Keep a glucagon injection kit to hand (see "Treating hypoglycaemia", below)
Preventing hypoglycaemia
In order to prevent hypoglycaemia whenever possible, it is necessary to understand why it happens and when it is most likely to happen. Then you should be able to take appropriate action to keep your blood glucose level above 4 mmol/l.
Hypoglycaemia has many causes:
Too much insulin or diabetes medication - these treatments stimulate the cells to remove too much glucose from the blood.
oo little food, particularly carbohydrates - if you don't eat regularly, you may not consume enough food to keep blood glucose levels within the normal range. Delayed or missed meals are the most common cause of hypoglycaemia.
Too much exercise - exercise uses up blood glucose.
Drinking alcohol - alcohol lowers blood glucose levels. Usually, as blood glucose levels fall, the liver releases stored glucose into the bloodstream. But alcohol interferes with this process. It is particularly dangerous for people with diabetes to drink on an empty stomach. Blood glucose levels can fall so fast so quickly that you may lose consciousness quite suddenly.
Pregnancy - pregnancy often makes women less aware of hypoglycaemia. Pregnancy also involves eating for two, which may require substantial changes in food intake and insulin doses.
Hypoglycaemia is most likely to occur:Just before meals, when blood glucose is naturally low
During or after strenuous exercise
When insulin is peaking
When you suspend your usual daily routines, particularly if your alcohol intake increases while your food intake falls
At night, particularly if you've been more active the day before, eaten less or consumed alcohol during the evening
Nighttime hypoglycaemia
Nighttime hypoglycaemia can be a problem for some people if they do not wake up. Common signs include damp sheets and pyjamas, nightmares, crying out in sleep, or feeling tired, irritable or confused on waking. A high early morning blood glucose level sometimes indicates hypoglycaemia during the night - the liver is stimulated to release glucose and 'overcompensates'.
To minimise risk of nighttime hypoglycaemia, test your blood glucose level periodically between 2 and 3 a.m. Determine how your level relates to your food, exercise, and insulin or medication the previous day and adjust them accordingly.
* Fits are quite common in young children, especially if hypoglycaemia occurs during the night. Don't worry - this is not epilepsy and generally causes no serious damage. As children grow older the fits become less frequent and most children grow out of them altogether.
For further information on hypoglycaemia in young children, please see "Diabetes and Your Child – Hypoglycaemia and Fitting"
Treating hypoglycaemia
It is best to treat hypoglycaemia with glucose or another fast-acting carbohydrate. All of the following contain 10 to 15 grams of carbohydrate and may be suitable for treating a hypo:
Two to three 5 gram glucose tablets.
Four to six ounces of orange juice.
A handful of raisins.
Half a can of a cola or other soft drink.
Six to 10 jellybeans or gumdrops.
Two teaspoons or cubes of sugar.
Two teaspoons of honey.
Six to eight ounces of non-fat or 1 percent milk.
It's a good idea to keep some of these blood glucose boosters with you at all times. Glucose tablets, raisins, and hard candies are compact, portable, and last a long time in desks, purses, lockers, and glove compartments.
Depending on what caused the hypoglycaemia and when you will eat your next meal, you may need to have an extra starchy snack - a sandwich or cereal bar, for example - to keep you going.
If a person is unable (or unwilling) to treat the hypoglycaemia themselves, then help may be needed in the form of a glucagon injection. Glucagon is a natural hormone, which raises the blood glucose level by encouraging the liver to release glucose into the bloodstream. It can be injected by a friend or family member, or, in the worst-case scenario, by a paramedic.
Wear some identification
People with diabetes should ideally wear medical identification bracelets or necklaces. At the very least, you should carry some form of identification on you that says that you have diabetes controlled by insulin or tablets. That way, if you are unable to communicate, anyone who finds you can quickly understand that you're suffering a complication of diabetes, and not some other problem.