Hypoglycemia

Signs, Symptoms, and Treatment for Hypoglycemia (Low Blood Glucose)

What are the signs of low blood glucose (hypoglycemia)?

Asian woman on subway feeling ill with hand on forehead

Since each person can experience the feelings of low blood glucose differently, there are a variety of symptoms that can be associated with a low. These signs and symptoms of a dropping blood glucose level can develop quickly. 

These symptoms are caused by the release of the “fight-or-flight” hormone called epinephrine (adrenaline). It is the release of adrenaline that causes the symptoms of low blood glucose such as thumping heart, sweating, tingling, and anxiety. 

Common signs and symptoms of low blood glucose 

  • Feeling shaky
  • Being nervous or anxious
  • Sweating, chills, and clamminess
  • Irritability or impatience
  • Confusion
  • Fast heartbeat
  • Feeling lightheaded or dizzy
  • Hunger
  • Nausea 
  • Color draining from the skin (pallor)
  • Feeling sleepy
  • Feeling weak or having no energy
  • Blurred/impaired vision
  • Tingling or numbness in the lips, tongue, or cheeks
  • Headaches
  • Coordination problems or clumsiness
  • Nightmares or crying out during sleep
  • In some cases: seizures 

How to tell if you have low blood glucose

The only sure way to know whether you are experiencing low blood glucose is to check your with a glucose meter or CGM. If you are experiencing symptoms and you are unable to check your blood glucose, treat the suspected hypoglycemia. You will need to check your glucose levels as soon as you can to make sure you have properly treated the low and to check that it has not bounced into a high blood glucose (hyperglycemia).  

Because it can be different from person to person, it's important to learn the signs and symptoms you have when your blood glucose levels are low. Taking time to write these symptoms down after you have a low can help you learn what to look out for and know that your blood glucose is low as soon as possible. It can also be a good idea to let those closest to you, (like friends, families, or roommates) know what sort of signs to look out for so they can help out if it becomes a severe hypoglycemia incident.  

Hypoglycemia unawareness

For most people, hypoglycemia symptoms start to appear when your blood glucose levels fall below 70 mg/dL. As unpleasant as they may be, these symptoms is how your body is telling you that you need to take steps to bring your glucose levels back up to range. However, many people can have a low and not feel any symptoms. This is called hypoglycemia unawareness. 

If you have hypoglycemia unawareness, you can't tell when your blood glucose is low, so you don’t know you need to treat it. This puts you at increased risk for severe hypoglycemia. You are also less likely to wake up when you're sleeping, and your blood glucose levels are dropping at night.  

If you have hypoglycemia unawareness, you need to take extra care to monitor your blood glucose by checking it frequently. This is even more important before and during critical tasks such as driving. A continuous glucose monitor (CGM) can sound an alarm when your blood glucose levels are low or start to fall. This can be a big help if you have hypoglycemia unawareness. 

Hypoglycemia unawareness occurs more frequently if you: 

  • Frequently have low blood glucose levels (this can cause you to stop sensing the symptoms
  • Have had diabetes for a long time 

If you think you have hypoglycemia unawareness, speak with your health care provider. Your health care provider may adjust/raise your blood glucose targets or your treatment plan to help prevent your blood glucose levels from dropping below your targets. 

It’s possible to get your early warning symptoms back by avoiding any, even mild, low blood glucose for several weeks. This helps your body re-learn how to react to low blood glucose levels. This may mean increasing your target blood glucose levels or adjusting your treatment plan. It may even raise your A1C level in the short term, but regaining the ability to feel symptoms of lows is worth the temporary rise in blood glucose levels. It is extremely important to work with your diabetes care team on a plan to manage your hypoglycemic unawareness. 

You may also start to have symptoms of low blood glucose when your when your blood glucose levels are higher than 70 mg/dL. This can happen when your blood glucose levels are very high and start to go down quickly. This can also happen if you have higher levels for a long period of time (your A1C is higher) and you bring your levels to your target range.  

If you're experiencing symptoms of lows when your blood glucose is in your target range, discuss it with your diabetes care team. 

How do you treat low blood glucose?

Sad teenage girl holding glass of orange juice

If you are experiencing a low, then you need to eat. Eating carbs is how you can raise your glucose levels. However, not all carbs are created equal. If your blood glucose is 70 mg/dL or below, try to follow the "15-15 Rule." 

15-15 Rule 

  • Consume 15 grams of fast-acting carbohydrates (carbs) to raise your blood glucose. Wait 15 minutes, then recheck your blood glucose again. 

  • If it's still below 70 mg/dL, or your continuous glucose monitor (CGM) doesn't show your blood glucose trending up, have another 15 grams of fast-acting carbs. 

  • Once your blood glucose is above 70 mg/dL, or is trending up on your CGM—and you won't be eating a meal soon—have a protein and carbohydrate snack (example: cheese crackers). This will help keep your blood glucose from dropping low again before your next meal. 

What are fast acting carbs? 

Fast acting carbs raise blood glucose quickly in your body. When food has higher fiber, fat, or protein , it slows down your body's ability to process it. Foods with chocolate or peanut butter are not the best choice for treating your low blood glucose. If you don't have fast-acting carbs, treat your low blood glucose with the food you have. It may take longer to bring your levels back up.  

Here are several ideas for fast acting carbs that you can eat when you have low blood glucose. Be sure to follow the 15-15 Rule.  

Examples of fast acting carbs 

  • Glucose tablets - small, chewable tablets that provide 4-5 carbs per tablet and come in a variety of flavors. They are typically found in the diabetes care section of a pharmacy.  

  • Glucose gel tube - a small tube of flavored gel that you squeeze into your mouth. One packet is approximately 15 carbs. They are typically found in the diabetes care section of a pharmacy. 

  • 1/2 cup (4 ounces) of juice or regular soda (not diet) 

  • 1 tablespoon of sugar or corn syrup (or, if older than 1 year, honey) 

  • Hard candies or jellybeans - Check the nutrition label for how many to eat for 15 carbs 

Additional info about treating a low glucose 

It is a good idea to carry fast acting carbs with you wherever you are, as a low can happen at any time. Try keeping shelf stable snacks with fast acting carbs in your car, at your work place, in your bag, or by your bed. 

While fast acting carbs are the best way to raise your glucose levels, you should have whatever is readily available that has carbs. Still follow the 15-15 rule. 

Young children usually need less than 15 grams of carbs to treat a low blood glucose. Infants may need 8 grams and small children may need 10 grams—this is individualized. Discuss how many carbs are needed to treat low blood glucose in children with their diabetes care team.