Symptoms of High Blood Sugar in People Without Diabetes

Hyperglycemia—high blood sugar—is commonly associated with people who have diabetes, but it can also impact those without diabetes. Like hyperglycemia in diabetes, the symptoms may include increased thirst, frequent urination, nausea, blurred vision, or fatigue. These symptoms may be subtle and easily go unnoticed, so the condition often goes untreated.

Nondiabetic hyperglycemia most often occurs if your body has undergone some type of trauma or stressful event. It can also occur as an ongoing issue in those with insulin resistance or prediabetes, a precursor to type 2 diabetes, or other conditions that affect insulin or stress hormones.

This article explains the causes of hyperglycemia in those without diabetes, potential symptoms, complications, and when to see a healthcare provider.

How to Prevent Hyperglycemia: A arrow pointing down on bread (decrease carbohydrate intake), cigarettes and trashcan (quit smoking), a scale (maintain healthy weight), person running (150 min of moderate-intensity exercise weekly), green vegetables with an arrow up (increase green vegetable intake), an x next to wine glass (limit or eliminate alcohol)

Verywell / Jessica Olah

What Does High Blood Sugar Feel Like?

The symptoms of nondiabetic hyperglycemia are similar to those of diabetic hyperglycemia. They can include:

  • Increased thirst
  • Frequent urination
  • Blurred vision
  • Nausea and vomiting
  • Abdominal pain
  • Fatigue
  • Headache

The recommended blood glucose range is 80 to 130 mg/dL, but hyperglycemia is diagnosed when levels reach above 180 mg/dL two hours after eating. However, symptoms may be felt with a blood glucose level between 160 mg/dL and 180 mg/dL.

Why Do People Without Diabetes Get High Blood Sugar?

High blood sugar in people without diabetes is often related to stress hormones or how your body processes insulin. It can happen during an injury or stressful event or may be an ongoing issue.

Insulin Resistance and Prediabetes

Insulin is a hormone produced by the pancreas that helps your cells store glucose. Insulin resistance is when your body doesn't respond to insulin as it should. If your cells become resistant to insulin and its effects, it causes a rise in blood sugar.

Prediabetes is when blood sugar is chronically elevated but not enough to be diagnosed with diabetes. It often occurs in those who already have some insulin resistance or in those whose pancreas isn't making enough insulin.

Other conditions, such as polycystic ovary syndrome (PCOS), that increase your risk of insulin resistance can also put you at risk of hyperglycemia.

Trauma or Stress

During stressful events, your body prepares by ensuring there is enough energy (sugar) available. Insulin levels decrease, stress hormones such as cortisol increase, glucose increases, and the body's tissues may be less sensitive to insulin. This may happen during traumatic injuries, serious illnesses, or during periods of intense anxiety and emotional stress.

Cushing's Syndrome

Cushing's syndrome is when the body is exposed to too much of the stress hormone cortisol. It can happen if there is an overproduction of cortisol in the body or it can occur with medications that contain cortisol, such as corticosteroids.

The high cortisol can increase your risk of prediabetes and hyperglycemia.

When to See a Healthcare Provider

If you have any of the following symptoms, make an appointment with your healthcare provider to get blood sugar tests for diabetes and prediabetes:

  • Frequent urination, especially at night
  • Excessive thirst
  • Unexplained weight loss
  • Increase in hunger
  • Blurry vision
  • Numb or tingling hands or feet
  • Fatigue
  • Very dry skin
  • Sores that heal slowly
  • More infections than usual

Hyperglycemia can happen suddenly after injury or illness. If you are experiencing any of the following symptoms, call 911 or have someone else call for you:

  • Fever
  • Ongoing diarrhea
  • Ongoing nausea or vomiting
  • Fruity breath
  • Severe headache
  • Seizure
  • Trouble breathing or talking
  • Weakness or confusion

The aforementioned signs and symptoms can be a signal of diabetic ketoacidosis or worse, and if left untreated can be life-threatening. Fortunately, immediate recognition and treatment of these symptoms can lead to rapid improvement of your high blood sugar levels.

Treating Nondiabetic Hyperglycemia

In nondiabetic hyperglycemia, resolution of the trigger or stressor that is causing the high blood sugar spike usually results in the resolution of your hyperglycemia. In some cases, your healthcare provider may recommend that you to take insulin or some other form of blood sugar-regulating drug to control your blood sugar levels.

If Cushing's Syndrome is causing hyperglycemia, your treatment will depend on the underlying cause of the high cortisol. Treatments may involve surgery or a reduction in medication.

If you do not have diabetes but have risk factors for diabetes, you may want to consult a diabetes specialist to diagnose your condition or identify prediabetes. Risk factors include obesity, a family history of diabetes, or mild symptoms of hypo- or hyperglycemia, You can also check your blood sugar levels at home with a glucose monitoring kit. 

Complications of High Blood Sugar in Nondiabetics

Obesity, a family history of diabetes, recent surgery, and certain medications increase your risk of complications. If nondiabetic hyperglycemia is not treated it can lead to:

  • Nerve damage (neuropathy)
  • Damage to the arteries and blood vessels, increasing your risk of heart attack and stroke
  • Slow healing
  • Development of infections by compromising your immune system

Preventing High Blood Sugar

Although more research needs to be done to determine the long-term impacts of hyperglycemia on nondiabetic patients—especially after acute injury—one thing is clear: living a healthy lifestyle that includes eating a balanced diet and routine exercise is the best way to avoid hyperglycemia and acute complications.

To prevent hyperglycemia:

  • Exercise: Engage in at least 150 minutes of moderate-intensity physical activity per week. This can help lower your blood sugar when it is high and keep your blood sugar levels steady over time. Children should get at least 60 minutes of physical activity each day.
  • Maintain a healthy weight: A healthy weight can help you lower your blood sugar levels. Ask your provider to help you create a weight-loss plan if you are overweight. Together you can set manageable weight loss goals.
  • Follow a meal plan: If you have access to a dietitian they can help you make a meal plan to help lower your blood sugar level. The key is to increase your green vegetable intake while decreasing the number of carbohydrates that you eat.
  • Do not smoke: Nicotine and other chemicals in cigarettes and cigars not only cause lung damage, but they also make your blood sugar levels harder to control. Quitting smoking—including e-cigarettes or smokeless tobacco which still contains nicotine—can help lower your blood sugar levels in the short and long term.
  • Limit or do not drink alcohol: Alcohol can increase your blood sugar level. Ask your healthcare provider about the frequency and amount of alcohol that is safe for you to drink.

A Word From Verywell

Sometimes you simply cannot avoid hyperglycemia. Genetic predisposition and traumatic events are out of our control, but living a healthy lifestyle that includes eating a balanced diet and routine exercise can help us avoid hyperglycemia and its many complications.

The symptoms of hyperglycemia may be vague, so monitoring how you're feeling is important. If you have a severe headache, sudden blurred vision, or notice a change in your eating and drinking patterns, seek immediate medical attention. Early diagnosis and treatment have been shown to lessen the risk of complications and poor outcomes.

9 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.
  1. MedlinePlus. High blood sugar - self-care.

  2. Centers for Disease Control and Prevention. Manage blood sugar.

  3. National Institute of Diabetes and Digestive and Kidney Diseases. Insulin resistance and prediabetes.

  4. Wong H, Singh J, Go RM, Ahluwalia N, Guerrero-Go MA. The effects of mental stress on non-insulin-dependent diabetes: determining the relationship between catecholamine and adrenergic signals from stress, anxiety, and depression on the physiological changes in the pancreatic hormone secretionCureus. Published online August 24, 2019. doi:10.7759/cureus.5474

  5. Sharma A, Vella A. Glucose metabolism in Cushing’s syndromeCurrent Opinion in Endocrinology, Diabetes & Obesity. 2020;27(3):140-145. doi:10.1097/MED.0000000000000537

  6. Centers for Disease Control and Prevention. Diabetes symptoms.

  7. Centers for Disease Control and Prevention. Diabetic ketoacidosis.

  8. National Institute of Diabetes and Digestive and Kidney Diseases. Cushing's syndrome.

  9. Department of Health and Human Services. Physical activity guidelines for Americans.

By Shamard Charles, MD, MPH
Shamard Charles, MD, MPH is a public health physician and journalist. He has held positions with major news networks like NBC reporting on health policy, public health initiatives, diversity in medicine, and new developments in health care research and medical treatments.