A blood sugar level below 70 mg/dL (3.9 mmol/L) is generally considered low blood sugar (hypoglycemia). It can cause sweating, shaking, hunger, dizziness, weakness, confusion, a fast heartbeat, or difficulty concentrating.
🩸 The 15-15 Rule
1. Check your blood sugar
If possible, confirm that it is below 70 mg/dL.
2. Take 15 grams of fast-acting carbohydrate
Examples include:
- 3–4 glucose tablets (depending on the tablet’s strength)
- About ½ cup (120 mL) of regular fruit juice
- About ½ cup of regular non-diet soft drink
- 1 tablespoon of sugar or honey
3. Wait 15 minutes
Don’t immediately take another large amount of sugar.
4. Check your blood sugar again
If it is still below 70 mg/dL, take another 15 grams of fast-acting carbohydrate and repeat the process.
5. Once it returns to normal
If your next meal is more than an hour away, having a small snack containing carbohydrate + protein may help prevent another drop.
⚠️ When it is an emergency
If the person is unconscious, having a seizure, severely confused, or unable to swallow, do not give food, sugar, or liquid by mouth because of the risk of choking. Use prescribed glucagon if available and seek emergency medical help immediately.
Important
The 15-15 rule is mainly for mild-to-moderate hypoglycemia in someone who is awake and able to swallow. People taking insulin or certain diabetes medicines can be particularly prone to low blood sugar, so recurrent episodes should be discussed with their healthcare professional.
