Often, prediabetes has no signs or symptoms.

Darkened areas of skin, a condition called acanthosis nigricans, is one of the few signs suggesting you are at risk for diabetes. Common areas that may be affected include the neck, armpits, elbows, knees and knuckles.

Classic red flags of type 2 diabetes to watch for include:

  • Increased thirst
  • Frequent urination
  • Fatigue
  • Blurred vision

When to see a doctor

Consult your doctor if you're concerned about diabetes or if you notice any type 2 diabetes signs or symptoms — increased thirst and frequent urination, fatigue, and blurred vision.

Ask your doctor about blood glucose screening if you have any risk factors for prediabetes, such as:

  • You're overweight, with a body mass index above 25.
  • You're inactive.
  • You're age 45 or older.
  • You have a family history of type 2 diabetes.
  • You're African-American, Hispanic, American Indian, Asian-American or a Pacific Islander.
  • You developed gestational diabetes when you were pregnant or gave birth to a baby who weighed more than 9 pounds (4.1 kilograms).
  • You have polycystic ovary syndrome, a common condition characterized by irregular menstrual periods, excess hair growth and obesity.
  • You have high blood pressure.
  • Your high-density lipoprotein (HDL) cholesterol (the "good" cholesterol) is below 35 milligrams per deciliter (mg/dL) — 0.9 millimoles per liter or mmol/L — or your triglyceride level is above 250 mg/dL (2.83 mmol/L).
  • You regularly sleep fewer than six hours or more than nine hours a night.
Jan. 26, 2012