What is hypoglycaemia?

Glucose is an important source of energy for your body. Hypoglycaemia (more commonly referred to as a hypo) means your blood glucose level is low, usually below 4mmol/L. When glucose levels are below 4mmol/L there may not be enough glucose or energy for your brain or body to use. Hypoglycaemia is a side effect of many diabetes medications or therapies; however. Hypos shouldn’t happen frequently, get worse or become severe enough for you to pass out. If they are, your diabetes therapies may need changing so that you have less hypos, so talk to your diabetes team.

What causes hypoglycaemia?

A mismatch between your diabetes therapies and food, early stages of pregnancy, more activity than normal or too much alcohol can all cause hypos. Sometimes there is no clear reason why your level has gone low.

Symptoms of hypoglycaemia

Symptoms of a hypo usually occur when the blood glucose levels fall to less than 4mmol/L. Typically early warning signs that your glucose level is going low include:

• Trembling
• Sweating
• Feeling hungry or tired
• Blurred vision

Advanced symptoms can be confusion or difficulty concentrating. In severe cases, loss of consciousness can happen. If you notice any warning signs that your blood glucose levels are too low, don’t ignore them. Treat your low glucose by eating something high in fast acting glucose such as fruit juice, glucose tablets, or a glucose drink.

You can have a hypo when you are asleep which can cause excess sweating, disturbed sleep and feeling tired when you wake up. If you think this might be happening to you, the easiest way to find out is to test your glucose level during the night. If you suspect or discover you are going low in the night, you will need to discuss ways to prevent this happening with your diabetes care team.

What if I don’t get any hypo symptoms at all?

You can have a hypo when you are asleep which can cause excess sweating, disturbed sleep and feeling tired when you wake up. If you think this might be happening to you, the easiest way to find out is to test your glucose level during the night. If you suspect or discover you are going low in the night, you will need to discuss ways to prevent this happening with your diabetes care team.

What if my glucose reading is above 4mmol/l but I feel hypo ?

If your blood glucose levels have been running on the high side for a while, your body has got used to it and is more sensitive when the level falls. So you may feel low even if you are not. There are ways to manage this and gradually get back on track with your levels so talk to your diabetes care team.

Treating hypoglycaemia

Hypoglycaemia can happen suddenly and it can usually be treated quickly and easily by taking a small amount of glucose; such as:

• A small glass of sugary (non-diet) drink
• 3 or more glucose tablets
• A small carton of pure fruit juice

You should have this fast-acting glucose food even if you are about to eat a meal.

After 15-20 minutes, re-test your glucose levels; if you are still less than 4mmol/L have another portion of high glucose food or drink.

Once your glucose level is more than 4mmol/L, you might need to have a longer-acting starchy carbohydrate food to keep your glucose from dropping again. Carbohydrates such as rice, pasta, potato, bread, cereal, can be part of a snack or meal. Other sources of dietary carbohydrate are milk, yogurt, and fruit. Less healthy carbohydrates are foods that contain sugar such as desserts and sugary beverages. Desserts such as pie, cake, biscuits, and chocolates can be poor choices to treat hypos because the high fat content slows the sugar getting into your blood.

It is up to you what you choose to eat to treat your hypo but it needs to do its job and act quickly to stop your levels falling. Also, tempting as it is, try not to have too much high-sugar food as you might end up with high blood glucose levels instead.

Never try to put food or drink into the mouth of someone who is drowsy or unconscious as they could choke.

Hypoglycaemia and driving

It takes up to 45 minutes for the brain to fully recover after a hypo so if you have had a hypo before or while you are driving, you must not start driving again for 45 minutes after blood glucose has returned to normal.

If you are a driver with insulin-treated diabetes, the DVLA advises that you:

• Check your blood glucose before and every two hours whilst you are driving (pull over to test)
• Your blood glucose should be 5.0mmol/l or above before you drive
• If it’s less than 4.0mmol/l or if you feel hypo, do not drive
• You should take your glucose monitor and blood glucose strips with you
• You should have some fast-acting carbohydrate, such as glucose tablets or fruit juice or a sugary drink, with you
• You should carry ID to show you have diabetes

Preventing a hypo

• Eat regular meals - don’t miss a meal
• Eat extra carbohydrate if you are more active than normal – such as a new exercise class, mowing the lawn or dancing the night away!
• Take your tablets and/or insulin injections at the right times
• Avoid drinking alcohol on an empty stomach or overindulging – if you have, eat a carbohydrate containing snack before bed as alcohol can cause a hypo, sometimes many hours after you have finished drinking
• Check your blood glucose levels regularly & more often if you have had a hypo
• Always carry a fast-acting carbohydrate with you, such as glucose tablets, fruit juice or a sugary drink