Hyperglycemia is high blood sugar, while hypoglycemia is low blood sugar. Because both can cause major health problems for people with diabetes, it’s important to keep blood sugar within a healthy range.

But high and low blood sugar doesn’t affect only people with diabetes. It can also occur in people who don’t have diabetes.

Here’s what you need to know about hypoglycemia and hyperglycemia, including symptoms, causes, and how to prevent it from happening to you.

Blood sugar levelSymptoms
trouble concentrating
fast heartbeat
Hyperglycemiaextreme thirst
dry mouth
frequent urination
blurry vision
shortness of breath

Hypoglycemia and hyperglycemia might sound similar, but these conditions occur under different circumstances — depending on whether you have diabetes.

How does hypoglycemia occur without diabetes?

Hypoglycemia usually happens to people living with diabetes, but it’s possible to have low blood sugar without diabetes.

Blood sugar, or glucose, is what your body uses for energy. After eating a meal or drinking a beverage, the hormone insulin allows sugar to enter your body’s cells, where it’s used for energy. Insulin is a hormone produced by your pancreas.

Hypoglycemia occurs when you have too much insulin in your bloodstream. This might happen if you don’t eat for several hours, such as 8 hours or more. A drop in blood sugar means there isn’t enough glucose in your bloodstream to fuel your brain and body.

Low blood sugar without diabetes can also occur if you take a medication that lowers your blood sugar. These include pain relievers like:

  • aspirin
  • birth control pills
  • steroids
  • blood pressure medication
  • some antibiotics

Other causes of low blood sugar without diabetes include binge-drinking (it affects how your liver releases glucose into your blood) and increased physical activity.

Plus, some medical conditions can increase the amount of insulin your pancreas produces. These include a pancreatic tumor, adrenal gland disorders, and hepatitis.

You could also experience low blood sugar if you have prediabetes, or if you eat a lot of refined carbohydrates, such as white bread, pasta, and pastries.

How does hypoglycemia occur with diabetes?

If you have diabetes, hypoglycemia can occur when you take too much insulin or another diabetes medication. Too much medication in your bloodstream causes your body’s cells to absorb too much glucose.

Hypoglycemia with diabetes can also occur when you eat less than normal or increase your level of physical activity.

How does hyperglycemia occur without diabetes?

Similarly, hyperglycemia can occur in people with and without diabetes.

If you don’t have diabetes, various factors can cause high blood sugar, either suddenly or gradually. For example, some medical conditions increase blood sugar. These include polycystic ovary syndrome and Cushing’s syndrome.

If you have an infection, your body might also release a high amount of stress hormones like adrenaline and cortisol. Too much of these hormones can interfere with your body’s ability to use insulin properly. As a result, your blood glucose level increases.

Other factors that can lead to hyperglycemia without diabetes include obesity and a lack of physical activity. You might also have higher blood sugar if you have a family history of diabetes.

How does hyperglycemia occur with diabetes?

The reason for hyperglycemia with diabetes depends on whether you have type 1 diabetes or type 2 diabetes.

If you have type 1 diabetes, your pancreas is unable to produce insulin. If you have type 2 diabetes, your pancreas doesn’t produce enough insulin to stabilize your blood sugar. In both conditions, glucose can build up in your bloodstream, resulting in hyperglycemia.

Your diabetes medication keeps your blood sugar within a safe range. If you don’t take your medication as instructed, you might experience blood sugar spikes. This can also occur due to poor eating habits, inactivity, or an infection.

Low blood sugar and high blood sugar can lead to serious diabetes complications. Untreated hypoglycemia can cause seizures, fainting, and even death.

Complications of untreated hyperglycemia include:

  • cardiovascular disease
  • kidney disease
  • nerve damage
  • infection
  • bone problems
  • amputation or death

How to prevent hypoglycemia with and without diabetes

If you don’t have diabetes, one of the best ways to prevent low blood sugar is to not skip meals. Eat five to six small meals throughout the day to keep your blood sugar within a healthy range.

If you increase your level of physical activity, you might need additional calories during the day to maintain your energy. Plus, learn how to recognize symptoms of low blood sugar, especially if you’re taking a medication that affects your blood sugar.

If you have diabetes, monitor your blood sugar level frequently, and talk with your doctor if you’re having symptoms of low blood sugar.

It’s important to monitor your glucose level if you make any changes to your eating schedule or if you increase physical activity. Ask your doctor about fast-acting carbohydrates like glucose tablets. If your blood sugar drops suddenly, a tablet can raise it to a safe level.

How to prevent hyperglycemia with and without diabetes

If you don’t have diabetes, you can prevent hyperglycemia with regular physical activity. Aim for 30 minutes at least 5 days per week.

Maintaining a healthy weight also keeps blood sugar within a safe range. This includes eating fewer refined carbohydrates, and eating more fresh fruits and vegetables.

If you have diabetes, always take your medication as directed. You can talk with your doctor, a diabetes educator, or a dietitian about healthy diabetes meal plans. You should also regularly monitor your blood sugar.

If you’re thinking about starting a new exercise routine, talk with your doctor first. They may need to adjust your medication.

Mild hypoglycemia and hyperglycemia are usually treatable at home.

If you have mild hypoglycemia, consuming a small amount of glucose (like a glucose tablet, fruit juice, or a piece of candy) can quickly raise your blood sugar.

If you skipped a dose of medication and have symptoms of mild hyperglycemia, taking your insulin or diabetes medication can help stabilize your blood sugar level.

Hypoglycemia is an emergency if you experience confusion, blurry vision, or seizures.

Hyperglycemia is an emergency if you have:

  • shortness of breath
  • confusion
  • coma
  • nausea and vomiting
  • fruity-smelling breath (a sign of ketoacidosis)

See a doctor if you’ve taken measures to keep your blood sugar within a healthy range, yet you still experience hypoglycemia or hyperglycemia.

Make an appointment if your blood sugar level persistently remains above 240 mg/dL, or if you have severe symptoms of hypoglycemia.

Hypoglycemia and hyperglycemia might sound similar, but these conditions are different.

Low blood sugar and high blood sugar can both lead to life threatening complications. So, it’s important that you learn how to recognize symptoms of each.

See a doctor if you develop severe symptoms, or if you’re unable to keep your blood sugar within a normal range — regardless of whether you have diabetes.