Insulin Resistance

Medically Reviewed by Michael Dansinger, MD on June 23, 2021

Insulin resistance is when cells in your muscles, fat, and liver don’t respond well to insulin and can’t use glucose from your blood for energy. To make up for it, your pancreas makes more insulin. Over time, your blood sugar levels go up.

Insulin resistance syndrome includes a group of problems like obesity, high blood pressure, high cholesterol, and type 2 diabetes. It could affect as many as 1 in 3 Americans. You might also hear it called metabolic syndrome.

You can't tell that you have insulin resistance by how you feel. You'll need to get a blood test that checks your blood sugar levels.

Likewise, you won’t know if you have most of the other conditions that are part of insulin resistance syndrome (high blood pressure, low "good" cholesterol levels, and high triglycerides) without seeing your doctor.

Some signs of insulin resistance include:

Things that can make this condition more likely include:

Your doctor will use these things to diagnose insulin resistance:

  • Questions. They’ll want to know about your family's medical history.
  • Physical exam. They’ll weigh you and check your blood pressure.
  • Blood tests. You might get:
  • Fasting plasma glucose test. This test measures your blood sugar after you haven’t eaten for at least 8 hours.
  • Oral glucose tolerance test. First, you'll take the fasting glucose test. Then you'll drink a sugary solution. Two hours after that, you'll take another blood test.
  • Hemoglobin A1c test. This blood test shows your average blood sugar level for the past 2 to 3 months. Doctors use it to diagnose prediabetes or diabetes. If you have diabetes, it helps show whether it's under control. You may need to take the test again to confirm the results.

When you have insulin resistance, your pancreas makes extra insulin to make up for it. For a while, this will work and your blood sugar levels will stay normal.

Over time, though, your pancreas won’t be able to keep up. If you don’t make changes in the way you eat and exercise, your blood sugar levels will rise until you have prediabetes. Your doctor will look for these blood test results:

  • Fasting plasma glucose test: 100-125
  • Oral glucose tolerance test: 140-199 after the second test
  • A1c results of 5.7% to 6.4%

If you aren’t able to manage prediabetes, you’ll be diagnosed with type 2 diabetes when your test levels reach:

  • Fasting plasma glucose test: 126 or higher
  • Oral glucose tolerance test: 200 or higher after the second test
  • A1c results of 6.5% or above

You can take steps to reverse insulin resistance and prevent type 2 diabetes:

  • Exercise. Go for at least 30 minutes a day of moderate activity (like brisk walking) 5 or more days a week. If you're not active now, work up to that.
  • Get to a healthy weight. If you're not sure what you should weigh or how to reach a weight loss goal, ask your doctor. You may also want to talk with a nutritionist and a certified personal trainer.
  • Eat a healthy diet. Think fruits, vegetables, whole grains, nuts, beans, fish, legumes, and other lean protein.
  • Take medications. Your doctor may prescribe a medication called metformin (Fortamet, Glucophage, Glumetza, Riomet) to help keep your blood sugar in check.

If metabolic syndrome goes untreated, it could lead to:

Show Sources


American Diabetes Association: "All About Insulin Resitance."

National Diabetes Information Clearinghouse: “Insulin Resistance and Pre-Diabetes.” 

The American Heart Association: “The Heart of Diabetes: Understanding Insulin Resistance.” 

Sundstrom, J. Diabetes Care, 2006. 

Eberly, L. Diabetes Care, 2006. 

Azadbakht, L. Diabetes Care

American Family Physician: “Insulin Resistance Syndrome.”

National Institute of Diabetes and Digestive and Kidney Diseases: “Insulin Resistance & Prediabetes.”

Mayo Clinic: “Metabolic syndrome.”

Cleveland Clinic: “Diabetes: Endocrinology Overview.”

American Diabetes Association: “Diagnosing Diabetes and Learning About Prediabetes

Anais Brasileiros de Dermatologia: [Association between skin tags and insulin resistance].”

American Academy of Dermatology: “Diabetes: 12 warning signs that appear on your skin.”

American Academy of Family Physicians: “Insulin Resistance.”

Medscape: “Insulin Resistance Clinical Presentation.”

Yonsei Medical Journal: “Obesity, Insulin Resistance and Cancer Risk.”

Current Alzheimer Research: “Insulin resistance and Alzheimer's disease pathogenesis: potential mechanisms and implications for treatment.”

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