By American Diabetes Association

Part of Managing Type 2 Diabetes For Dummies Cheat Sheet

A blood glucose reading below 70 mg/dL is called hypoglycemia (low blood glucose). Low blood glucose can be dangerous when you have type 2 diabetes, so it’s important to recognize the symptoms of low blood glucose and understand how to treat it.

Warning signs of lows

The symptoms of low blood glucose can be different for each person, but classic warning signs of lows include

  • Shaking
  • Nervousness or anxiety
  • Sweating, chills, or clamminess
  • Irritability (or, with severe lows, anger, sadness, or stubbornness)
  • Color draining from the skin
  • Hunger and nausea
  • Rapid heartbeat
  • Weakness, fatigue, or sleepiness
  • Headache
  • Tingling or numbness in the lips or tongue
  • Nightmares or crying out during sleep
  • Lightheadedness, dizziness, or confusion
  • Difficulty seeing or blurry vision
  • Unusual behavior such as clumsiness or slurring of words
  • Anger, sadness, and/or stubbornness
  • Seizures or becoming unconscious with severe lows

Rule of 15

The “Rule of 15” is an easy method for treating low blood glucose. The method is called the Rule of 15 because you treat lows with approximately 15 grams of fast-acting carbohydrate (such as glucose tablets or gels, fruit juice, or regular soda) and then retest your blood glucose after 15 minutes. Before using this method, ask your doctor to make sure it’s right for you. To put the Rule of 15 to use, follow these steps:

  1. Test your blood glucose.
  2. If your blood glucose is below 70 mg/dL, eat or drink something with 15–20 grams of carbohydrate.
  3. Wait 15 minutes.
  4. Test again and if your blood glucose is still below 70 mg/dL, eat or drink another 15 grams of carbohydrate.
  5. Repeat until normal.

Consider eating a snack after an episode of low blood glucose if your planned meal is an hour or more away.