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What are the red flags of type 2 diabetes?

Type 2 diabetes is a chronic condition that affects how your body processes blood sugar (glucose). With type 2 diabetes, your body either resists the effects of insulin — a hormone that regulates the movement of sugar into your cells — or doesn’t produce enough insulin to maintain normal glucose levels. Over time, high blood sugar can damage nerves and blood vessels, leading to complications like heart disease, stroke, kidney disease, blindness, erectile dysfunction, foot problems and hearing loss. Recognizing the signs and symptoms of type 2 diabetes and understanding your risk factors can help you get diagnosed sooner and start treatment to prevent or delay complications.

What are the major risk factors for type 2 diabetes?

The major risk factors for developing type 2 diabetes include:

  • Weight. Being overweight or obese increases your risk. Excess fat causes insulin resistance, especially fat around the belly.
  • Inactivity. The less active you are, the greater your risk. Physical activity helps control your weight, uses up glucose as energy and makes your cells more sensitive to insulin.
  • Family history. Having a parent or sibling with type 2 diabetes increases your risk. You’re also more likely to develop it if you have conditions linked to type 2 diabetes, like polycystic ovary syndrome or nonalcoholic fatty liver disease.
  • Age. The risk increases as you get older, especially after age 45.
  • Race. Having dark skin, African American heritage, Hispanic/Latino, American Indian, or Asian American heritage increases your risk.
  • Prediabetes. If your blood sugar levels are higher than normal but not high enough for a type 2 diabetes diagnosis, you have prediabetes.
  • Gestational diabetes. If you developed gestational diabetes when pregnant, your risk for developing type 2 diabetes increases.
  • Polycystic ovary syndrome. For women, having polycystic ovary syndrome — a common condition characterized by irregular menstrual periods, excess hair growth and obesity — increases the risk.
  • High blood pressure. Having blood pressure over 140/90 mm Hg is linked to an increased risk.
  • Abnormal cholesterol and triglyceride levels. If you have low levels of high-density lipoprotein (HDL), or “good,” cholesterol, high levels of triglycerides, or both, your risk is higher.

You can reduce your risk by losing weight, exercising regularly, eating healthy foods, limiting alcohol and by not smoking. If you have prediabetes, aggressive lifestyle changes can actually return blood sugar levels to normal.

What are some early signs and symptoms of type 2 diabetes?

In the early stages of type 2 diabetes, you may have no symptoms at all or very mild ones. Over time, signs can develop gradually. Some of the early signs include:

  • Increased thirst and frequent urination. Excess sugar building up in your bloodstream causes fluid to be pulled from the tissues. This may leave you thirsty. As a result, you may drink — and urinate — more than usual.
  • Increased hunger. Without enough insulin to move sugar into your cells, your muscles and organs become depleted. This triggers intense hunger.
  • Weight loss. Despite eating more than usual to relieve hunger, you may lose weight. Without the ability to metabolize glucose, the body uses alternative fuels stored in muscle and fat, leading to a loss of calories.
  • Fatigue. Your body’s cells are deprived of sugar, your main source of energy. This can lead to tiredness and fatigue.
  • Blurred vision. High blood glucose levels associated with diabetes can cause fluid to be pulled from the lenses of your eyes, affecting your ability to focus.
  • Slow healing sores or frequent infections. High blood sugar reduces the effectiveness of your immune system, making it harder to heal from sores or fight off infections.

Some people with type 2 diabetes have symptoms so mild they go unnoticed. It’s estimated that as many as a third of people who have type 2 diabetes don’t know it.

What health complications are caused by uncontrolled type 2 diabetes?

Over time, elevated blood sugar levels from uncontrolled diabetes can damage your nerves, eyes, kidneys, and other organs. Potential complications include:

  • Heart and blood vessel damage (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).
  • Nerve damage (neuropathy). Excess sugar can damage the walls of the tiny blood vessels (capillaries) that nourish your nerves, especially in the legs. This can cause tingling, numbness, pain and weakness.
  • Kidney disease (nephropathy). The kidneys contain millions of tiny blood vessel clusters that filter waste from your blood. Diabetes damages this delicate filtering system. Severe damage can lead to kidney failure or irreversible end-stage kidney disease, requiring dialysis or a kidney transplant.
  • Eye damage (retinopathy). Diabetes affects the small blood vessels in the retina, the light-sensitive layer of tissue in the back of your eye. New blood vessels may form and cause bleeding, blocking light from reaching the retina. Retinopathy can progress to blindness.
  • Foot damage. Nerve damage, circulation problems and infections can cause diabetic foot problems. Left untreated, cuts and blisters can lead to serious infections. Severe damage may require toe, foot or leg amputation.
  • Skin and mouth conditions. High blood sugar creates an environment that allows yeast to grow, for instance, causing itchy skin rashes. Gum disease (periodontitis) is also more likely.
  • Hearing impairment. Hearing problems are twice as common in people with diabetes. Experts aren’t sure why but think it may involve damage to the small blood vessels in the inner ear.
  • Alzheimer’s disease. Type 2 diabetes can increase the risk of dementia, including Alzheimer’s disease. The poorer your blood sugar control, the greater the risk appears.

Complications may be preventable or manageable if caught early. That’s why regular medical checkups are important. Over time, complications can be disabling or even life-threatening.

What tests diagnose type 2 diabetes?

Diagnosing type 2 diabetes includes:

  • Glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. An A1C of 6.5 percent or greater on two separate tests indicates diabetes. A result between 5.7 and 6.4 percent is considered prediabetes.
  • Random (non-fasting) blood sugar test. A blood sample is taken at a random time. A random blood sugar of 200 milligrams per deciliter (mg/dL) or higher suggests diabetes. This test must be confirmed with a fasting blood glucose test.
  • Fasting blood sugar test. Your blood is drawn after an overnight fast. A fasting blood sugar level less than 100 mg/dL is normal. A level of 100 to 125 mg/dL is considered prediabetes. A level of 126 mg/dL or higher on two separate tests indicates diabetes.
  • Oral glucose tolerance test. For this test, you fast overnight and then drink a sugary liquid. Your blood sugar levels are tested periodically for the next two hours. Prediabetes is diagnosed if your blood sugar level is between 140 and 199 mg/dL after two hours. Diabetes is diagnosed if the two-hour blood sugar level is 200 mg/dL or higher.

Sometimes a diagnosis can be made based on symptoms and blood sugar levels. Other times, oral glucose tolerance testing is needed. Don’t try to diagnose yourself. See a doctor to have the proper tests.

Summary of the major red flags and symptoms

The major warning signs that indicate an increased risk of having or developing type 2 diabetes include:

  • Being overweight or obese, especially if you carry excess weight around your belly
  • Darker skin, such as African American, Hispanic, Native American or Asian heritage
  • Physical inactivity
  • Family history of diabetes
  • History of gestational diabetes
  • Diagnosed prediabetes, higher-than-normal blood sugar levels
  • High blood pressure over 140/90 mm Hg
  • Abnormal cholesterol levels with low HDL and/or high triglycerides

Increasing thirst, frequent urination, fatigue, blurry vision, slow healing of sores or infections and unexplained weight loss are possible signs of type 2 diabetes. See your doctor if you have any of these symptoms.

Left uncontrolled, type 2 diabetes can cause serious health complications like heart disease, kidney disease, eye problems, nerve damage, skin conditions, hearing impairment and Alzheimer’s disease. Getting tested is important, especially if you have any risk factors. You may have no signs at all or mild ones that go unnoticed.

By recognizing your risks factors and possible symptoms sooner, you can get diagnosed and start treatment to prevent the onset of diabetes or manage it properly to avoid complications. Work with your doctor to control blood sugar levels through medications as needed, regular exercise, weight control and a healthy diabetes-friendly diet.


Type 2 diabetes has become incredibly common, mainly due to rising obesity rates and sedentary lifestyles. However, it doesn’t have to be a devastating diagnosis. Understanding your risks, recognizing possible symptoms and getting the right screening tests can lead to earlier diagnosis and treatment.

Treating prediabetes aggressively with lifestyle changes may even return blood sugar levels to a normal range. Maintaining a healthy weight through diet and exercise, taking prescribed medications as directed, self-monitoring blood sugar levels, getting regular medical care and managing stress can help people with type 2 diabetes avoid severe complications and enjoy a high quality of life.