Endocrine Community
Get answers. Share advice. Learn More

What Is Prediabetes?

Causes, Symptoms, Diagnosis, and Treatment

A prediabetes diagnosis can seem scary, but it’s really an opportunity to take control of your health before there are any serious consequences. We’re here to empower you with clear answers to all your pressing Qs on how to reverse prediabetes and the changes you can make right now to ensure it never turns into Type 2.

In This Article: 
What is Prediabetes? Causes | Detecting Prediabetes Symptoms | Diagnosis | Risk Factors | Complications and Comorbidities | Lifestyle | Treating Prediabetes

What is prediabetes?

Prediabetes is a warning sign that type 2 diabetes (T2D), which affects 1 in 3 American adults, might be in your future. Typically, this means that your blood sugar is higher than normal, but not yet high enough for a type 2 diagnosis. 

Luckily, prediabetes does not have any serious symptoms. Think of it as a call to action. “The way I explain prediabetes to my patients is that your body is struggling to keep your blood glucose levels in a healthy range,” says nutritionist Lauren Antonucci RD. “You shouldn’t panic, but you should start making real changes in your diet and lifestyle to prevent your blood sugar from rising and turning into type 2.”

Prediabetes Fast FactsInfographic by Lauren Hunter


What causes prediabetes?

Insulin is a hormone made by your pancreas that helps your body convert glucose into fuel. When you eat a meal, the carbohydrates in your food are converted into glucose, otherwise known as blood sugar. 

That glucose stays in your bloodstream until your pancreas releases insulin. The insulin acts like a key that opens your cells to allow the glucose to enter, where it’s then used to fuel your body. Without insulin or when insulin is not working effectively, that glucose stays stuck in your bloodstream and accumulates, causing your blood sugar to rise.

During type 2 diabetes, your pancreas can still produce insulin, but that insulin gradually becomes less effective at helping the glucose into your cells. 

Prediabetes is an indicator that your body is beginning to stop using insulin as efficiently as it should. In other words, your body is starting to become resistant to insulin. When your body resists insulin, the glucose levels in your blood rise, which is how you develop prediabetes and, if that process is not stopped and allowed to progress, type 2 diabetes.

What are prediabetes symptoms to watch out for?

“If prediabetes was easy to detect, you wouldn’t have people go years and years before getting diagnosed with type 2 diabetes,” says Antonucci. 

Typically, adults experience either no symptoms at all, or the insulin resistance symptoms are so gradual or slight they may go unnoticed for years. Sometimes, though, there are warning signs. These include:

  • Increased thirst
  • Increased hunger
  • Fatigue
  • Unexplained weight loss, even if eating more
  • Frequent urination

The last symptom happens because excess sugar in your bloodstream triggers your body to make more urine in order to flush the glucose out. The more you urinate, the more likely you are to become dehydrated, which can lead to a cycle of increased hunger and thirst signals.

Diabetes symptoms men experience can also cause sexual issues such as erectile dysfunction (ED) and decreased sex drive.

Risk factors and warning signs of prediabetesThese are some of the prediabetes risk factors and warning signs to watch for.

How do doctors diagnose prediabetes?

Diabetes is a measure of levels of sugar in your bloodstream. Physicians check this in two different ways

1. A standard blood glucose test

This requires you to fast before a blood test, so your PCP or endocrinologist can check the level of glucose in your bloodstream at any given time. Ideally, fasting glucose levels should be 99 mg/dL or lower. If your fasting blood glucose levels are between 100 and 125mg/dL, it could be considered prediabetes, says Martha McKittrick RD. “I like to have people get a second test done, to make sure it’s accurate,” she says. A reading higher than 126 mg/dL indicates diabetes.

2. An A1C blood test 

The test for A1C, or hbA1c, is a non-fasting blood test that measures the average amount of glucose in your blood stream over a period of three months and is measured in percentages. A healthy percentage is under 5.7%. A result between 5.7 and 6.4% suggests prediabetes. Anything higher than 6.5% indicates diabetes.

A person who is prediabetic may not always show symptoms. In fact, the majority don’t. Oftentimes, an asymptomatic person will only get a prediabetes diagnosis if their general physician gives them a blood glucose test or checks their hbA1C readings and finds an atypical result. 

For this reason, one of the most important things you can do is get a physical exam with bloodwork once every year. “Your bloodwork can tell you if your glucose levels are too high, and whether or not you’re heading in the right direction as far as controlling them before you develop type 2 diabetes,” Antonucci says.

Although most people don’t show noticeable symptoms of prediabetes, if you are experiencing fatigue, excessive hunger, excessive thirst, and frequent urination, it’s better to be safe than sorry. Make an appointment to get your glucose levels checked ASAP.

What are the risk factors and warning signs of prediabetes? 

Your risk of developing prediabetes increases when you have any of the following:   

  • Unhealthy diet. Diets high in sugar and processed foods raise your blood pressure and increase your level of LDL, or “bad cholesterol” in addition to your blood glucose, putting you in danger of developing prediabetes.
  • Excess weight. If you’re medically overweight, you’re at a high risk for developing prediabetes. This is especially true if you carry a lot of extra weight in your abdomen, which is known as visceral fat and can play a role in insulin resistance.
  • A sedentary lifestyle that includes little to no physical exercise. Being very inactive contributes to insulin resistance and weight gain, both of which can then lead to prediabetes. Aim to move around at least 30 minutes per day, even it is just to go on a walk.
  • A family history of type 2 diabetes. Prediabetes has a hereditary factor. If someone in your immediate family has T2D—or has had T2D in the past — you are more likely to develop prediabetes and type 2 diabetes yourself. Your race and ethnicity also affect your likelihood of developing prediabetes. There is a genetic component, but research has shown that racial disparities in who develops diabetes have more to do with socio-economic status and the accessibility of health care and healthy food in your community than your genes.
  • A history of gestational diabetes. Diabetes during pregnancy can signal a higher risk for prediabetes and type 2 diabetes later on.
  • SmokingThe nicotine in cigarettes decreases the sensitivity of your cells to insulin, which raises the glucose in your blood. Other chemicals in cigarettes cause inflammation and make it harder for those cells to absorb insulin.
  • Advanced age. The older you are, the more at risk you become. At age 45, your likelihood of developing prediabetes starts to rise. By retirement age, almost 25% of seniors over 65 have prediabetes. 

Does prediabetes cause complications?

Prediabetes doesn’t have any complications, but if left unchecked, it can develop into type 2 diabetes, which can then bring on severe complications. Some complications of T2D include:

  • Hypertension
  • Stroke
  • Kidney damage
  • Eye damage 
  • Neuropathy
  • Skin infections
  • Sleep apnea
  • Diabetes rash

Is prediabetes reversible?

Absolutely! You can turn back your prediabetes by adopting lifestyle changes, including:

  • Evaluating food choices. Contrary to popular opinion, you don’t have to eliminate the foods you love. For the best chance at long-term success, work with your dietitian to create a meal plan that still includes your favorite foods with slight alternations if necessary, so you don’t feel deprived and can stick to it long-term. Some examples of this might include switching out white rice for cauliflower rice as an accompaniment to your usual dishes, or swapping “zoodles” made from squash or other vegetables for pasta so you can still enjoy your favorite recipes with less starch.
  • Exercise. Exercise is a great way to reverse prediabetes for a number of reasons. First, a fitness regimen can help you shed the pounds that increase your risk for prediabetes without restrictive dieting. Additionally, when you exercise, your body uses more glucose, which helps clear it out of your bloodstream. Finally, exercise activates a cell receptor called GLUT-4, which actually helps absorb glucose out of your bloodstream and move it into your cells. Cardio and weights both are exercises that help activate the GLUT-4 mechanism. The American Diabetes Association recommends at least 150 minutes of moderate physical activity each week, which most commonly averages out to 30 minutes, five times a week. But you can also divide it up into longer workouts on days when you have more time available if you know you will be too busy to exercise on others.
  • Losing weightIf your doctor has medically advised weight loss for prediabetes and you don’t know where to begin (or you’ve already tried every diet with no results), ask for help. Think about it: You hire an accountant for your taxes, you pay a mechanic to service your car rather than trying to figure it out yourself. Similarly, if weight loss is important for you to protect your health in the future and avoid diabetes, it’s worth it to enlist professionals to assist you in your weight loss journey. Losing just 5 to 10% of your body weight can significantly reduce your risk of developing type 2 diabetes and eliminate your prediabetes, so invest in a nutritionist and trainer if you have found it too challenging to lose weight in the past. Many health plans pay for diabetes educators and physical therapy, and your doctor can work with you to connect you to services that are available to help you succeed within your budget. Uninsured? Nutritionist-recommended apps like Cronometer and Mindful Eating Tracker ($2.99) take the focus off of calorie counting and educate you about what you are eating while they help you make better food choices.
  • Medication. If you are at a very high risk of developing type 2 diabetes after being diagnosed with prediabetes because of comorbidities such as obesity, you doctor may recommend a medication such as metformin, which keeps your liver from making more glucose when you don’t need it, so your glucose levels stay within a safer range.

What are the treatments for prediabetes?

If you catch it early, prediabetes can usually be reversed with diet and exercise. Depending on how high your blood sugar is when you’re first diagnosed, your doctor might elect to put you on one medication or a combination in order to get your glucose back down to a healthy level.

“Going on medication for prediabetes treatment is not cut and dry,” Antonucci says. “Your blood sugar levels, A1C, medical history, and other complications might put you in a situation where medication should be added to your treatment plan to avoid type 2 – it’s case by case, so work with your doctor to arrive at the best treatment for you.”

What is a prediabetes diet?

A diet for prediabetes looks a lot different than a typical American one. “I like to tell my clients to reserve half of your plate for vegetables, a quarter of your plate for protein, and a quarter of your plate for healthy carbohydrates, such as whole grains and fruit,” says McKittrick. 

A person with prediabetes should not eat processed carbohydrates that are high in sugar, but instead get carbohydrates from whole grains, fruits, legumes, and starchy vegetables (in moderation). “If you want to cut out carbs, you certainly can, but you don’t have to,” McKittrick says. “They taste good, they give you energy, and usually it's not sustainable to give them up completely.” 

Also shoot for 25-30-grams of fiber from food each day, as fiber-rich foods such as oatmeal and crunchy vegetables improve insulin resistance and keep you fuller, longer.

Frequently Asked Questions: FAQs

Can diabetes go away? 

Yes! Prediabetes and type 2 diabetes are reversible conditions for most people who commit to a combination of diet, exercise, and lifestyle changes. 

What are the warning signs for prediabetes? 

The primary indicator of prediabetes is a hemoglobin A1C level of 5.7% or greater. Other risk factors include being overweight, being 45 years or older, smoking, physical inactivity, or having a family history of prediabetes. 

What level of A1C is dangerous? 

An A1C level between 5.7 and 6.4% means your blood sugar is higher than normal. An A1C reading of 6.5% indicates diabetes, and an A1C level of 8% or above is a sign of uncontrolled diabetes, meaning you have a higher risk of developing complications such as kidney damage or stroke.

What’s the best way to reverse prediabetes? 

The best way is a combination of 1) whatever way works for you and 2) whatever way is sustainable.

Some people can control their blood sugar with modifications to their diet and lifestyle, while others need medication as well. The most important thing is to collaborate with your doctor to find the treatment plan that gets your blood sugar in check and keeps it there so that you don’t develop T2D.

Is diabetes curable? 

No, but it is reversible. If you catch your prediabetes before it morphs into type 2 diabetes, you can turn back the process and avoid becoming diabetic. Even T2D can be kicked if it is caught before it is allowed to progress. So, take heart. You can do this!

Prediabetes Fast Facts 

  • More than 84% of people with prediabetes don’t know it.

  • Because it often lacks symptoms, prediabetes can go years without being detected.

  • 88 million people in the US have prediabetes.

  • 34% of Americans have prediabetes.
Continue Reading
Treatment of Diabetes: The Diabetic Diet