Low Blood Sugar in Diabetes: Spot It and Treat It with the 15 15 Rule

For people with diabetes, the usual worry is blood sugar that is too high. Yet blood sugar that is too low is dangerous too, and it can come on faster. This is called hypoglycaemia. According to the CDC, blood sugar below 70 mg/dL is low, and below 54 mg/dL is severely low.

The signs

Common symptoms include:

• A fast heartbeat, shaking, and sweating.
• Feeling anxious, irritable, or confused.
• Dizziness and hunger.

As it gets worse, a person may look very weak, have trouble walking or seeing clearly, behave strangely, have a seizure, or even faint. Some people feel no symptoms at all, which makes the risk greater. Checking blood sugar regularly helps catch it early.

What causes it

The CDC lists several common causes, including:

• Too much insulin, or insulin at the wrong time.
• Too little carbohydrate for the insulin dose.
• More or longer physical activity than usual.
• Drinking alcohol.
• Hot, humid weather and sudden changes in daily routine.

The 15 15 rule

When blood sugar is below 70 mg/dL, the CDC recommends the 15 15 rule:

1. Eat or drink 15 grams of fast acting carbohydrate.
2. Wait 15 minutes, then check your blood sugar again.
3. If it is still below 70 mg/dL, repeat the first step.
4. Once it is back in range, eat a snack or meal with protein and carbohydrate.

Examples of 15 grams of carbohydrate:

• Half a cup, about 120 ml, of fruit juice or regular, not diet, soft drink.
• One tablespoon of sugar, honey, or syrup.
• Three to four glucose tablets.
• Hard sweets or jelly sweets, using the label to check the amount.

Avoid treating a low with chocolate, cakes, fruit, or beans. Their fat and fibre slow down how fast sugar is absorbed. Babies and small children may need less, so ask a doctor first.

When it is very low

Below 55 mg/dL, the 15 15 rule may not be enough, and the person may not be able to help themselves. The CDC names a glucagon injection, prescribed by a doctor, as the best treatment in this situation. After glucagon is given, call emergency services straight away. If someone with a low has fainted, do not give them food or drink by mouth.

Tell the people around you

Because low blood sugar can cause confusion, the people around you should know the signs, how to check blood sugar, and what to do. Family, workmates, and the teachers of a child with diabetes should all understand it.

If you have lows often, talk to your doctor. Your medicine dose may need adjusting. A Coapotek pharmacist can also help explain how to use diabetes medicines and blood sugar meters.

Sources

1. Centers for Disease Control and Prevention. Low Blood Sugar (Hypoglycemia), 16 May 2024.
2. Centers for Disease Control and Prevention. Treatment of Low Blood Sugar (Hypoglycemia), 15 May 2024.