5 warning signs you might have high blood sugar, according to doctors

• High blood sugar is a widespread problem that can lead to chronic health issues over time.
• Potential symptoms of high blood sugar include fatigue, increased thirst, and more frequent urination.

More than a third of Americans have high blood sugar levels that could lead to health issues like diabetes, nerve damage, increased risk of heart disease, and kidney problems — and the majority of people with the condition have no idea, according to the CDC.

One of the challenges of identifying high blood sugar is that symptoms may not be clear right away, said Dr. Mary Korytkowski, emeritus professor of medicine in endocrinology at the University of Pittsburgh School of Medicine.

"If blood sugar is mildly elevated, it usually happens so gradually that people might not notice," she told Business Insider.

Normal blood sugar levels are typically within 70 to 99 milligram of sugar per deciliter of blood while fasting, and below 140 mg/dL after eating.

Blood tests can determine whether your blood sugar is high, and a growing number of wearables offer real-time updates on how your blood sugar levels change over time.

While brief spikes of elevated blood sugar aren't necessarily cause for concern, chronic high blood sugar, or hyperglycemia, can develop into prediabetes or eventually type 2 diabetes.

Pay attention to potential indicators that your blood sugar levels could be high, such as excessive tiredness, increased thirst, unusual weight loss, and slower healing, some of which overlap with signs and symptoms of diabetes.

Knowing what to look for can flag when it's time to see a doctor and help you get a head start on making healthy changes, according to Dr. Libu Varughese, endocrinologist and medical advisor at Aeroflow Diabetes.

"Make an appointment to get your levels checked and consider lifestyle improvements to help lower or promote more balanced blood sugar, such as low sugar intake and low carbohydrate intake. Increasing activity such as exercising is another lifestyle strategy to consider," Varughese told Business Insider. "The earlier you're able to integrate these lifestyle choices to lower blood sugar levels, the better to prevent diabetes."

Unusual tiredness can be a warning of high blood sugar

Potential symptoms of high blood sugar can be difficult to distinguish from other health issues — for example, high blood sugar can cause you to feel more tired than usual.

"That's a tough one because fatigue has so many causes, but it can be a symptom of high blood sugar, feeling tired and more sluggish," Korytkowski said.

A sense of exhaustion without an easy explanation is good reason to get checked out to rule out a range of health issues.

"If someone feels like they're getting enough sleep and this is new, it's worth going to see a doctor," Korytkowski said.

More frequent bathroom breaks might mean elevated blood sugar

A classic indicator of diabetes is needing to pee more frequently.

If you have more blood sugar than your body is able to handle, it falls on the kidneys to try to get rid of that extra glucose, causing an increase in urination, Korytkowski explained.

While the "normal" number of times to urinate per day can vary widely and depends on factors like hydration, changes to your habits can be a clue to get your blood sugar levels tested.

Increased thirst is a symptom of hyperglycemia

Dehydration can occur if your body is overloaded with glucose and trying to filter it out, since the glucose pulls water along with it.

That can leave you feeling dry and persistently thirsty and, in the context of other symptoms, should prompt a visit to the doctor.

Cuts that won't heal or frequent infections are a warning sign

Delayed healing is another hallmark of high blood sugar, according to Varughese.

Higher levels of glucose can impair your circulation and immune system, making it harder for your body to make needed repairs to damages tissues.

Similarly, dealing with infections more often can also be related to high blood sugar, or a number of other health issues, so it's worth getting medical attention.

Unexplained weight loss is a red flag

For type 2 diabetes, overweight or obesity can be a risk factor.

But in some cases, losing weight is a potential symptom of type 1 diabetes, since the body can lose calories while trying to get rid of excess sugar through the urine.

"If they're eating more and not gaining weight, or are losing weight, they could be losing glucose and losing calories," Korytkowski said.

High blood sugar isn't the only explanation of sudden, unexpected weight loss, but other possible causes could include serious illnesses (including cancer) so don't hesitate to check with your doctor.

How to manage high blood sugar

Strategies to reduce blood sugar and diabetes risk are the same habits that work for overall health, according to Barbara Eichorst, registered dietitian and vice president of Health Care Programs at the American Diabetes Association.

A nutritious diet, regular exercise, and getting enough rest and relaxation are all linked to lower blood sugar levels.

"Eating healthy, physical activity, sleep and stress management benefit people with diabetes, prediabetes and anyone who wants to feel better on a daily basis," she said.