What are the causes of hypoglycemia?

When blood sugar levels fall to around 70 (mg/dl) and lower, this is considered hypoglycemia and symptoms usually follow. There are many reasons why someone might experience hypoglycemia. Simple things, like forgetting to eat or pushing yourself too hard can cause blood sugar levels to drop, and there are less common reasons, like tumors or enzyme deficiencies. For common causes, it’s reasonably easy to prevent symptoms as it generally comes down to paying attention to your body’s signals and eating regular snacks.

Let’s take a look at some known causes of hypoglycemia.



  • Waiting too long to eat or skipping a meal. This is known as fasting hypoglycemia, and most people experience this at some point and have minor symptoms. People who deal with hypoglycemia on a regular basis are likely familiar with a wide variety of symptoms just by not eating soon enough.
  • Going to sleep without eating a snack about 60 mins prior. It’s possible to experience hypoglycemia while sleeping and going hours without eating.1 If you go to sleep on an empty stomach, the chances are higher of having nighttime symptoms. For those who have unawareness or more severe cases, wearing a continuous glucose monitor (CGM) while sleeping is a good idea. This device monitors your glucose levels and will sound an alarm if your sugar goes too high or too low.

Alcohol can cause hypoglycemia

  • Not eating enough carbohydrates.1 Foods that are carbohydrates provide the necessary sugars for our bodies to pull from. Eating snacks and meals or drinking shakes that have carbs in them will keep your glucose levels balanced and for a longer period of time.
  • Drinking a lot of alcohol on an empty stomach. Doing this may stop the liver from sending stored glucose out into the bloodstream.2 Alcohol can also make it difficult to sense the symptoms of hypoglycemia and could lead to severe hypoglycemia with symptoms that are very serious and potentially life-threatening.1 It’s always a good idea to eat something before drinking alcohol, otherwise, the alcohol will go into your bloodstream faster, and for a hypoglycemic person, this is bad news.
  • Strenuous exercise or exercising for a long period of time. Physical activities use up a lot of energy, which means a lot more glucose. As a result, blood sugar levels could drop faster and bring on symptoms. Glucose levels could continue to drop for up to 24 hours after physical activities, especially if you push yourself beyond your normal routine.1

This does not mean that you can’t exercise, be a body-builder, go bike riding, or do any number of physical activities. It just means that it’s necessary to fuel up before working yourself by consuming a snack, and if you plan to exercise for a long period, then eat or drink something during the workout. When finished, make sure to consume a source of protein and you should be good to continue with your day.

  • Sickness. At times, it is difficult to eat enough or keep food in the stomach when you’re sick, but being sick can make blood sugar levels drop.1 Be mindful of this if or when you are sick and try to consume things to keep your sugar up. It may help to drink something more often instead of making yourself eat food. The body will use up fluids faster than foods as it does not require digestion.

Sickness can cause hypoglycemia

  • Stress. Taxing ourselves or becoming stressed will use up more glucose compared to when we are emotionally at ease. Stress is all around hard on the body and has many negative effects on our health. If you have a stressful lifestyle or are under a lot of pressure, look for outlets to relax. While at work, go for an easy walk on break, either indoors or outside, listen to music, sit outside in the sun for fifteen minutes, look into taking up a hobby, spend time with people, have alone time, etc.
  • Diabetic medications, like sulfonylureas and meglitinides, two medications used for diabetes that is known to cause hypoglycemia.1 In type 1 diabetes, not enough insulin is made by the pancreas, and in type 2 diabetes, cells are less responsive to insulin. With diabetes, insulin is not as effective, which isn’t good because insulin helps our body use sugar as energy from ingested carbohydrates. Insulin also regulates our blood sugar level, keeping it from going too high or too low.3

Since insulin is unable to do its job as it was designed, glucose accumulates in the bloodstream and could rise to alarmingly high levels.3 Taking medicines for diabetes, like insulin or pills, is meant to bring high blood sugar levels down or help the body produce more insulin.1

You could experience hypoglycemia by taking too much insulin compared to the amount of glucose in your bloodstream,3 or if the medication isn’t matched to the amount of food eaten—if you eat less than usual there’s less glucose for your body to use.1

The usual solution would be to take insulin or medication meant to bring down blood glucose levels. Your physician should help you find the dosage that works best with your eating and exercise routines.3Medications can cause hypoglycemia


  • Medications. Those used to treat kidney failure and other illnesses. Some of these medications are; quinine or Qualaquin (for malaria), salicylates (a pain reliever), sulfa (antibiotic medication), pentamidine (meant to treat a severe kind of pneumonia).4
  • Serious illnesses. Conditions of the heart, or liver, like severe hepatitis, issues with the kidney which may prevent the body from releasing medications as it should, and the build-up of medication could alter blood sugar levels. Continual malnourishment, anorexia nervosa, or bulimia may prevent the body from effectively producing glucose.2
  • Bypass surgery. Known as alimentary hypoglycemia. Foods travel through the stomach into the small intestine too fast and can result in hypoglycemia.4



  • Too much insulin and tumors. Circumstances that may cause an increase or overproduction of insulin are; insulinoma, which is a rare pancreas tumor; nesidioblastosis, meaning the increased size of pancreatic beta cells which function in making insulin; and other types of tumors.2
  • Hormone deficiencies. Conditions of the adrenal and or pituitary glands that cause a shortage of essential hormones that manage the production of glucose. Children with hormone deficiencies are more likely to experience hypoglycemia than adults.2 Low hormone levels for epinephrine, cortisol, glucagon, and growth hormone can all affect glucose levels.4
  • Rare enzyme deficiencies that make it difficult for the body to break down food.4

Learn about your conditionThere are many causes of hypoglycemia, some are less understood than others. If you have a specific condition that is known to cause symptoms, make sure to educate yourself about it and learn manageable ways to keep blood glucose levels balanced.

The best thing to do is know your body and pay attention to how you’re feeling, how long it’s been between meals, your activity and stress level, understand side effects of medications, eat foods that are healthy carbs, and check your blood glucose regularly. The more you understand, the easier it will be to make adjustments, which should reduce any major frustrations you may be feeling as a result of this condition.

Published April 18, 2017


If you have any questions, comments, or personal experiences please feel free to share in the comment section below! 


1) Low Blood Glucose (Hypoglycemia). National Institute of Diabetes and Digestive and Kidney Diseases. Published August 2016. Accessed April 14, 2017.

2) Mayo Clinic Staff. Diseases and Conditions: Hypoglycemia. Mayo Clinic. Published January 20, 2015. Accessed April 14, 2017.

3) Mayo Clinic Staff. Diseases and Conditions Hypoglycemia: Causes. Mayo Clinic. Published January 20, 2015. Accessed April 14, 2017.

4) FACT SHEET: Nondiabetic Hypoglycemia. Hormone Health Network. October 2013. Accessed April 14, 2017.

2 thoughts on “ CAUSES

  1. Great post Angela, this is a really informative read and although i have heard of Hypoglycemia before, because my mum is disabled, and her friend has Diabetes and general blood sugar issues. But i didn’t realise until i read this article what sort of things can cause Hypoglycemia, and what a wide variety of causes it can be – As someone who exercises a lot, i definitely have to make sure i keep my body well fuelled so i don’t drop my sugar levels too low.

    Anyway thanks so much for sharing this, i will direct anyone here that will find support in this.

    1. Hi Marley,

      I’m glad this page was helpful and informative to you! When I researched the different causes, I myself was surprised by how many things can cause low blood sugar.

      Thanks for stopping by!

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