How Hypoglycemia Is Diagnosed

Hypoglycemia can be diagnosed when a person's blood sugar falls lower than 70 milligrams per deciliter (mg/dL). Blood sugar that falls lower than 54 mg/dL is considered severely low and may make you faint, so you will need medical attention right away.

Untreated hypoglycemia can be dangerous. If you have been diagnosed with diabetes and are experiencing hypoglycemia, your treatment plan may need to be adjusted. If you have symptoms of hypoglycemia and have never been diagnosed with diabetes, your healthcare provider will need to find the cause.

This article covers how hypoglycemia is diagnosed and how you can check for hypoglycemia at home if you have diabetes. It also explains what tests healthcare providers order for people who have never received a diabetes diagnosis.

how hypoglycemia is diagnosed

Verywell / Laura Porter

Self-Checks/At-Home Testing

If you're a person with diabetes, especially when you're newly diagnosed and beginning treatment, you will likely encounter episodes of hypoglycemia on occasion.

In fact, it's not uncommon for people with diabetes to experience hypoglycemia once or twice per week. This may even happen when they are managing their blood sugar closely.

Check your blood sugar with a blood glucose meter if you begin to experience any of the following symptoms of hypoglycemia:

If your blood sugar reading is 70 mg/dL or below, you will need to treat it right away with fast-acting carbohydrates such as three to four glucose tablets, half a banana, or a granola bar.

Labs and Tests

If you do not have diabetes, schedule a visit with your healthcare provider if you keep having symptoms of hypoglycemia. Your healthcare provider will do a physical exam, medical history, and ask you questions about your symptoms.

Blood Tests

Your healthcare provider will need to see if your blood glucose level is low when you're having symptoms.

If you have symptoms of hypoglycemia after you eat, your healthcare provider may have you come back after a meal to check your blood glucose.

You may also need to have your blood drawn and sent to the lab to analyze your insulin levels and/or other substances in your blood.

Glucose enters cells with help from insulin and glucose transporters.

If you do have hypoglycemia, the cause can be as simple as a medication you're taking that can lead to low blood sugar. Medications that can cause hypoglycemia include:

  • The antibiotic Bactrim (sulfamethoxazole and trimethoprim)
  • Beta blockers
  • Monoamine oxidase inhibitors (MAOIs)
  • Haldol (haloperidol)

Hypoglycemia can sometimes occur after an alcohol binge, too. If it's not due to medications or alcohol, your healthcare provider may do additional testing to find out what the underlying cause is. Other possible causes include a hormonal deficiency or an illness like kidney disease or hepatitis.

Differential Diagnoses

If you don't have diabetes and you have symptoms of hypoglycemia yet your blood sugar levels are normal, there's something else going on. In fact, there's a long list of conditions that your symptoms could be attributed to.

The most common non-diabetes causes include:

  • Liver, kidney, or cardiac disease
  • Malnutrition
  • Hormonal deficiencies
  • Medication side effects
  • A metabolic disorder like hyperthyroidism
  • A complication of bariatric surgery

Hypoglycemia in a non-diabetic person can occur as a result of an infection like pneumonia, or the body's extreme immune response to infection (sepsis).

That said, having diabetes also increases your risk of developing infections and being hospitalized for them. If you have diabetes and are experiencing severe hypoglycemia, your healthcare provider may still evaluate you for infection or another underlying cause that needs to be treated.

Your healthcare provider may do additional testing to look for the cause of your symptoms depending on what they are and your family and medical history.

Hypoglycemia Unawareness

If you have diabetes and your blood glucose levels are too low, but you notice few or no symptoms, it is probably due to hypoglycemia unawareness.

When you have repeated episodes of hypoglycemia, you can stop showing symptoms. In this case, hypoglycemia commonly happens at night when you're unaware that your glucose levels have dropped.

If you are diagnosed with diabetes, beginning a treatment plan soon after your diagnosis can be beneficial, depending on your needs and preferences. Your healthcare provider will work with you to form a plan, which may include:

A continuous glucose monitor can be helpful in detecting hypoglycemia, especially at night, because it alerts you when your levels get too high or too low.

Your healthcare provider will work with you to get your levels under control so this stops happening. Even two to three weeks of avoiding hypoglycemia can restore your body's awareness.

Summary

Hypoglycemia (low blood sugar) is common in people with diabetes. If you have previously been diagnosed with diabetes and keep having hypoglycemia symptoms, your healthcare provider may need to adjust your treatment plan or evaluate you for another underlying cause.

If you have never been given a diabetes diagnosis and are having symptoms of hypoglycemia, you should still be evaluated. There is a chance your provider will find that you have diabetes, but other conditions like hyperthyroidism or even a medication you are taking could also be the cause.

A Word From Verywell

Blood sugar varies throughout the day due to a number of reasons, from what and when you eat to your physical activities and even stress. But if you feel that you are on a hypoglycemia rollercoaster or that you are frequently having hypoglycemia symptoms, then something needs to be done. Being newly diagnosed with diabetes can be frightening, but the sooner you are diagnosed, the sooner you can begin managing your glucose and get back to the things you enjoy.

Frequently Asked Questions

  • Could I be diagnosed with hypoglycemia if I am not diabetic?

    Yes, but it is rare. In these instances, you may have low blood sugar for several reasons:

    • Pre-diabetes
    • Stomach surgery complications
    • A rare enzyme deficiency
    • Medication side effect
    • Excess alcohol consumption
    • Liver, heart, or kidney disease
    • Hormone imbalance
    • Tumors that produce insulin or similar hormones
  • What type of healthcare provider can I see to test for hypoglycemia?

    Your primary care healthcare provider can check your blood sugar levels and may refer you to a specialist. An endocrinologist usually diagnoses and treats hypoglycemia and other hormone-related diseases, including diabetes. 

  • Can I test myself for hypoglycemia at home?

    Yes. You can check to see if your diabetes medication raises your risk of hypoglycemia or to see if the symptoms you are experiencing are due to low blood sugar. You can purchase an over-the-counter testing kit, which requires you to do a finger prick to obtain a blood droplet. This is placed on a test strip, which offers a digital reading of your blood sugar level.

12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Mary Shomon
Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution."