Type 2 Diabetes - Red Flags

Type 2 diabetes can cause lots of damage before it's diagnosed.
By Madeline Vann, MPH
Medically reviewed by Pat F. Bass III, MD, MPH

Type 2 diabetes begins as a "silent" condition, because before it does noticeable damage to your body, it has no distinguishing symptoms, other than high blood sugar levels that can be found with a blood test.

But there are signs that diabetes is present, although they are easily ignored. In fact, of the nearly 21 million Americans with type 2 diabetes, about six million don’t know they have it.

Possible symptoms of type 2 diabetes include:

* Being more thirsty than usual
* Feeling more hungry than usual
* Feeling more tired than usual
* Needing to urinate more than usual, especially at night
* Blurry vision
* Unplanned weight loss
* Sores that don’t go away

"There are a lot of people who don’t have symptoms," says Vivian Fonseca, MD, professor of medicine and pharmacology and chief of the section of endocrinology at Tulane University Health Sciences Center in New Orleans.

Dr. Fonseca says that many people believe a "silent" condition like diabetes is nothing to worry about because they don’t feel any different. However, higher-than-normal blood sugar levels do damage at the microvascular level (affecting the smallest of your blood vessels), even if you can’t feel it.

"Even milder diabetes with no symptoms can continuously do damage over the years, so that’s where the problem lies," says Fonseca. "When sugar goes from 115 to 130 [mg/dL], you have diabetes. So for example, you can have eye damage, but no knowledge of that happening."

Diabetic retinopathy, which is the result of damage to the blood vessels in the eye that causes progressive vision loss, is one physical change that is most closely linked to the onset of type 2 diabetes. Data from the Diabetes Prevention Program suggest that this gradual damage to the eye occurs in about 12 percent of people within three years of the diagnosis of diabetes.

Although early damage to your eye can be seen using the equipment at your eye doctor’s office, many people will not know they have diabetic retinopathy until it has progressed far enough to interfere with their vision.