TL;DR

Many people with diabetes have symptoms such as excessive thirst, frequent urination, fatigue, blurred vision, slow wound healing, recurrent infections, and unexplained weight changes. However, diabetes develops gradually, and many people spend years with prediabetes or insulin resistance before blood sugar rises enough to meet the definition of diabetes. During this earlier stage, people may experience weight gain around the waist, fatigue after meals, sugar cravings, difficulty losing weight, poor sleep, and other metabolic problems. A simple blood test, including fasting glucose and hemoglobin A1c, can often identify these problems before diabetes develops.

What Are the Symptoms of Diabetes?

Classic symptoms include:

  • Excessive thirst
  • Frequent urination
  • Increased hunger
  • Fatigue
  • Blurred vision
  • Slow healing cuts and wounds
  • Frequent infections
  • Numbness or tingling in the hands or feet
  • Unexplained weight loss (more common in Type 1 diabetes)
  • Weight gain or difficulty losing weight (common in Type 2 diabetes)

Many people develop symptoms gradually over months or years.

Prediabetes Usually Comes First

Type 2 diabetes rarely develops overnight. Most people first develop insulin resistance, a condition in which the body’s cells stop responding normally to insulin. To compensate, the pancreas produces more insulin, often for years before blood sugar rises enough to be called diabetes. This stage is often called prediabetes and is an ideal time to intervene because lifestyle changes can often prevent or delay the progression to diabetes.

Symptoms of Insulin Resistance

Insulin Resistance Can Affect More Than Blood Sugar

Insulin resistance affects much more than blood sugar. It is linked to a wide variety of health conditions, and improving insulin sensitivity may improve many seemingly unrelated symptoms.

Nearly 9 out of 10 people with prediabetes don’t know they have it. Likewise, about 1 in 4 people with diabetes remain undiagnosed, making regular screening especially important for adults who are overweight, inactive, or have a family history of diabetes.

How Is Diabetes Diagnosed?

Test Normal Prediabetes Diabetes
Fasting glucose <100 100–125 ≥126
A1c <5.7% 5.7–6.4% ≥6.5%

Hemoglobin A1c reflects your average blood sugar over the previous two to three months and is one of the most useful tests for identifying prediabetes and diabetes.

What If You Have Prediabetes or Diabetes?

If you have symptoms of diabetes or your blood sugar or A1c is elevated, don’t ignore it. The earlier diabetes and prediabetes are identified, the easier they are to manage. Many people can slow or even prevent the progression from prediabetes to Type 2 diabetes through lifestyle changes. Talk to your healthcare provider about appropriate testing, including fasting glucose and hemoglobin A1c, especially if you have risk factors such as obesity, a family history of diabetes, or high blood pressure.