Low blood glucose: Know the signs and steps to take | CAC
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Low blood glucose: Know the signs and steps to take

You may recognize the feeling—feeling hungry, dizzy, sweaty or just a little bit "off." These signs of hypoglycaemia, or low blood glucose, mean it's time to take action.

What causes low blood glucose?

For most people, low blood glucose refers to anything below 3.89 mmol/L, (70 mg/dL) although your number may be different.1

Low blood glucose can be caused by taking too much medication, not having enough to eat or exercising. In fact, hypoglycaemia can occur up to 12 hours after you've been physically active.1 Don't be too hard on yourself, though. Fifty percent of the time, there's no way of knowing what led to the low.1 Focus on the treatment, then consider what might have caused it once you're back in range..

Low blood glucose warning signs

Everyone is different, but low blood glucose is often marked by:2

  • Feeling weak or light headed
  • Trembling or shaking
  • Sweating
  • Headache or dizziness
  • Lack of concentration/behaving strangely
  • Crying or irritability
  • Hunger
  • Numbness around the lips and fingers

Not sure about how you're feeling? Check. A quick blood glucose test is a simple way to see if you are going low.

Some people don't feel any warning signs of low blood glucose. This is known as "hypoglycaemia unawareness."1 If you can't feel low blood glucose coming on, talk to your healthcare provider about carefully monitoring your blood glucose levels, fine-tuning your insulin therapy, considering a continuous glucose monitor or other strategies that can help you avoid lows.1

How to treat a low

When you're low, you have one goal: bring up your blood glucose levels. Some people use the "15/15 Rule" as a reminder—eat 15 grams of carbohydrates, then wait 10 or 15 minutes and check your level again. Repeat this process as needed.2,3

For 15 grams of carbohydrates, try:1,2

  • 150 ml or ¾ cup of regular, not diet, soft drink
  • 1/2 glass of fruit juice
  • 3 teaspoons or 15 ml of sugar or honey
  • 6 or 7 jellybeans or hard candies
  • Premeasured glucose tabs or gel

Once your blood glucose has stabilized in a safe range, eat longer-acting carbohydrates such as a sandwich, yogurt or fruit.2

When you can't eat to treat

If untreated, low blood glucose can quickly become an emergency. In cases of severe hypoglycaemia, you may be unable to eat something to treat the low. While this is unlikely to be an issue if you have type 2 diabetes, people with type 1 diabetes should prepare for it.1 That's why your healthcare provider has probably recommended that you carry a glucagon kit. When given to you by another person, this injection of the hormone glucagon quickly stimulates your body to produce the glucose you need.2

Talk to your friends and family about what signs to look for and, if needed, how to use the glucagon kit in an emergency.

Low blood glucose: Act now

Below 3.89 mmol/L1 or 72 mg/dL

(Your number may vary.)

Signs of low blood glucose2

  • Weakness
  • Light headedness
  • Trembling
  • Shaking
  • Sweating
  • Headache
  • Dizziness
  • Lack of concentration
  • Behavior changes
  • Crying
  • Irritability
  • Hunger
  • Numb lips or fingers

The 15-15 rule for treating low blood glucose3

1. Take 15 grams of fast-acting carbohydrates

2. Wait 10 to 15 minutes

3. Check blood glucose and, if it's still low, repeat

Handy treatments for lows2

1/2 can of regular soda (not diet)

1/2 glass of fruit juice

3 teaspoons of sugar or honey

6-7 jellybeans

Premeasured glucose tabs or gel

1International Diabetes Federation. Diabetes education modules 2011: hypoglycaemia. Available at: http://www.idf.org/education/resources/modules-2011/download. Accessed June 30, 2015.

2Diabetes Australia. Hypoglycaemia. Available at: http://www.diabetesaustralia.com.au/Understanding-Diabetes/What-is-Diabe.... Accessed June 30, 2015.

3Medline Plus. 15/15 rule. Available at: http://www.nlm.nih.gov/medlineplus/ency/imagepages/19815.htm. Accessed June 30, 2015.


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