What is low blood sugar?

Low blood sugar or hypoglycemia is when your blood sugar falls to less than 4 mmol/L (or 70 mg/dl). This can happen to people with diabetes who take insulin or other diabetes medication. Some people with diabetes develop symptoms of low blood sugar at slightly higher levels. If your blood sugar levels are high for long periods of time, you may have symptoms and feel poorly when they drop closer to 5.6 mmol/L (or 100 mg/dl).

What symptoms might I have if my blood sugar is low?

If your blood sugar is low, you may experience one or more of the following symptoms:

  • Sweating
  • Shaking
  • Palpitations
  • Hunger
  • Nausea
  • Anxiety
  • Tingling
  • Fatigue
  • Weakness
  • Headache
  • Dizziness
  • Confusion
  • Difficulty concentrating
  • Difficulty speaking
  • Loss of consciousness

What causes low blood sugar?

There are many factors that cause low blood sugar including:

  • Taking too much diabetes medication or insulin
  • Missed or delayed meals
  • Eating a smaller meal than normal
  • Increased or unexpected exercise

How can I prevent low blood sugar?

The best way to prevent low blood sugar is to monitor your blood sugar levels frequently and be prepared to treat it promptly at all times. You and a close friend or relative need to learn the symptoms and should always carry glucose tablets or other sources of fast-acting carbohydrate.

What do I do if I think my blood sugar is low?


Test your blood sugar

(If unable to test, treat as if blood sugar is less than 4 mmol/L or 70 mg/dl)


If your blood sugar is low (less than 4 mmol/L or 70 mg/dl), eat or drink 15-20 g of a fast-acting carbohydrate. Choose one of the following:

  • 120ml (1/2 cup) of juice
  • 120 ml (1/2 cup) of regular soda
  • 6-8 jelly beans
  • 3 glucose tablets
  • 1 tablespoon of sugar
  • 1 tablespoon of honey
  • 2-3 small dates
  • 240 ml (1 cup) of low fat or skimmed milk


Wait 15 minutes then retest your blood sugar. If your blood sugar is still less than 4 mmol/L or 70 mg/dl, repeat step 2 until blood sugar is more than 4 mmol/L or 70 mg/dl


If your next meal is more than an hour away, eat a small snack:

  • 1 slice of wholegrain bread OR ½ whole wheat Arabic bread
  • 1 serving of fresh fruit (1 small apple, orange or banana)
  • 2-3 small dates
  • 2 biscuits
  • 1 small pot of low-fat or skim plain yogurt
  • 1 small glass/bottle of low-fat or skimmed laban


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