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Signs You Have Diabetes and Don't Know It

Doctor explains diabetes symptoms to look out for. 
FACT CHECKED BY Emilia Paluszek

Chances are you know someone with diabetes. "37.3 million Americans, or 11.3% of the population, had diabetes" in 2019, according to the American Diabetes Association and "Nearly 1.9 million Americans have type 1 diabetes, including about 244,000 children and adolescents." In addition, "Of the 37.3 million adults with diabetes, 28.7 million were diagnosed, and 8.5 million were undiagnosed." Often signs of diabetes are missed, but  Dr. Bayo Curry-Winchell, Urgent Care Medical Director and Physician, Carbon Health, and Saint Mary's Hospital tells Eat This, Not That! Health, symptoms to watch out for and how to help prevent diabetes. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.

1

Why is Diabetes Commonly Undiagnosed?

Doctor with glucometer and insulin pen device talking to male patient at medical office in hospital.
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Dr. Curry-Winchell explains, "Diabetes is associated with a variety of symptoms such as an increase in thirst, changes in vision, and fatigue which can make it difficult to consider you might have diabetes. My patients often report seeing the eye doctor or thinking they need to get their vision checked or often associate the fatigue with an inadequate amount of sleep."  

2

What Can Happen if Diabetes is Untreated

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"Because diabetes affects so many organs in the body, if left untreated, it can lead to serious complications such as permanent vision loss, heart disease, and long-term kidney disease," Dr. Curry-Winchell says.

According to the Mayo Clinic, "Long-term complications of diabetes develop gradually. The longer you have diabetes — and the less controlled your blood sugar — the higher the risk of complications. Eventually, diabetes complications may be disabling or even life-threatening. Possible complications include:

  • Cardiovascular disease. Diabetes dramatically increases the risk of various cardiovascular problems, including coronary artery disease with chest pain (angina), heart attack, stroke and narrowing of arteries (atherosclerosis). If you have diabetes, you're more likely to have heart disease or stroke.
  • Nerve damage (neuropathy). Excess sugar can injure the walls of the tiny blood vessels (capillaries) that nourish your nerves, especially in your legs. This can cause tingling, numbness, burning or pain that usually begins at the tips of the toes or fingers and gradually spreads upward.
    Left untreated, you could lose all sense of feeling in the affected limbs. Damage to the nerves related to digestion can cause problems with nausea, vomiting, diarrhea or constipation. For men, it may lead to erectile dysfunction.
  • Kidney damage (nephropathy). The kidneys contain millions of tiny blood vessel clusters (glomeruli) that filter waste from your blood. Diabetes can damage this delicate filtering system. Severe damage can lead to kidney failure or irreversible end-stage kidney disease, which may require dialysis or a kidney transplant.
  • Eye damage (retinopathy). Diabetes can damage the blood vessels of the retina (diabetic retinopathy), potentially leading to blindness. Diabetes also increases the risk of other serious vision conditions, such as cataracts and glaucoma.
  • Foot damage. Nerve damage in the feet or poor blood flow to the feet increases the risk of various foot complications. Left untreated, cuts and blisters can develop serious infections, which often heal poorly. These infections may ultimately require toe, foot or leg amputation.
  • Skin conditions. Diabetes may leave you more susceptible to skin problems, including bacterial and fungal infections.
  • Hearing impairment. Hearing problems are more common in people with diabetes.
  • Alzheimer's disease. Type 2 diabetes may increase the risk of dementia, such as Alzheimer's disease. The poorer your blood sugar control, the greater the risk appears to be. Although there are theories as to how these disorders might be connected, none has yet been proved.
  • Depression. Depression symptoms are common in people with type 1 and type 2 diabetes. Depression can affect diabetes management."

3

Who is at Risk for Diabetes?

Diabetic woman taking blood sample with lancet pen at home.
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Dr. Curry-Winchell states, "All ages are at risk for diabetes. The disease can affect anyone and if left untreated or not controlled, can lead to serious complications that can affect your quality of life."

4

How to Help Prevent Diabetes

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Dr. Curry-Winchell explains, "There are two types of diabetes and it's important to highlight that you can't prevent the onset of type 1 diabetes. Although scientists have discovered possible connections that may be the cause, research is ongoing to find the exact cause at this time.   For type 2 diabetes, mild to moderate exercise such as taking a walk and lifting weights like traditional dumbbells a couple of days a week and eating a diet that is balanced but also sustainable can help prevent diabetes."

The Mayo Clinic states, "Type 1 diabetes can't be prevented. However, the same healthy lifestyle choices that help treat prediabetes, type 2 diabetes and gestational diabetes can also help prevent them:

  • Eat healthy foods. Choose foods lower in fat and calories and higher in fiber. Focus on fruits, vegetables and whole grains. Strive for variety to prevent boredom.
  • Get more physical activity. Aim for about 30 minutes of moderate aerobic activity on most days of the week, or at least 150 minutes of moderate aerobic activity a week.
  • Lose excess pounds. If you're overweight, losing even 7% of your body weight — for example, 14 pounds (6.4 kilograms) if you weigh 200 pounds (90.7 kilograms) — can reduce the risk of diabetes.
    Don't try to lose weight during pregnancy, however. Talk to your doctor about how much weight is healthy for you to gain during pregnancy.
    To keep your weight in a healthy range, focus on permanent changes to your eating and exercise habits. Motivate yourself by remembering the benefits of losing weight, such as a healthier heart, more energy and improved self-esteem.
  • Sometimes medication is an option as well. Oral diabetes drugs such as metformin (Glumetza, Fortamet, others) may reduce the risk of type 2 diabetes — but healthy lifestyle choices remain essential. Have your blood sugar checked at least once a year to check that you haven't developed type 2 diabetes."  

5

Increase in Thirst

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"If you notice you are drinking more fluids and it's not associated with increased activity or exercise — this could be a sign of diabetes," says Dr. Curry-Winchell.

Your body is responding to an increase in blood sugar (glucose) circulating in your bloodstream. To decrease the amount of glucose, your kidneys increase the amount of time you need to urinate — which means more trips to the restroom and increased water intake as your body attempts to replenish itself."

6

Change in Vision

Mature woman takes off her glasses and massages eyes.
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According to Dr. Curry-Winchell, "Vision changes like blurry vision due to high levels of glucose causes blood vessels in your eye to increase in size (swell) and become friable causing leakage."  

7

Fatigue

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Dr. Curry-Winchell explains, "Although you would think the increase in glucose should lead to more energy, it's the exact opposite. The increased sugar is not being used, instead it's circulating in the blood therefore your organs like your brain are not able to use it."  

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more
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