Long-term complications of type 2 diabetes can be divided into two main categories: macrovascular complications and microvascular complications.
Macrovascular complications involve the large blood vessels and include heart attack and other forms of cardiovascular disease.
Microvascular complications involve the small blood vessels and include diabetic retinopathy (eye disease), neuropathy (nerve disease), and nephropathy (kidney disease).
All of these complications can be prevented, and in some cases, reversed or slowed by a combination of:
  • Blood sugar control
  • Blood pressure control
  • Blood cholesterol control
You should discuss your level of control (and how to maintain or improve it) with your doctor at every appointment.

Cardiovascular Disease

Cardiovascular disease is the number-one cause of poor health and death among people with type 2 diabetes.
While some degree of arteriosclerosis (hardening of the arteries) occurs in everyone with age, diabetes accelerates the rate at which it develops and progresses.
Lowering your risk of cardiovascular disease — or treating it, if you have it — includes a combination of lifestyle changes along with medication, including:
  • Quitting smoking if you smoke
  • Sticking to a low-fat diet
  • Getting regular physical activity
  • Taking prescribed medications to lower blood pressure and cholesterol
  • Taking diabetes medications to lower blood sugar

Retinopathy (Eye Disease)

In diabetic retinopathy, high blood sugar weakens the capillaries (the tiny blood vessels) that supply the retina, the light-sensitive layer of tissue at the back of the inner eye.
The capillaries then swell, become blocked, or leak blood into the center of the eye, blurring vision.
In advanced stages, abnormal new blood vessels grow. When these new vessels leak blood, the result can be severe vision loss or blindness.
In some cases, fluid leaks into the center of the macula, the part of the eye responsible for detailed, central vision.
This is called macular edema, and it can also cause vision loss.
In its early stages, diabetic retinopathy does not cause noticeable symptoms, but it can be detected with a dilated eye exam.

That's why the American Diabetes Association (ADA) recommends that all people with type 2 diabetes get a dilated eye exam from a qualified eye doctor (an optometrist or ophthalmologist) at the time of diagnosis and yearly thereafter.
Both retinopathy and macular edema can be treated with laser surgery, and certain drugs can be used to treat macular edema.

Neuropathy (Nerve Damage)

Neuropathy associated with diabetes, or diabetic neuropathy, can affect any nerve in your body.
Most commonly, it affects the nerves in the feet, legs, hands, and arms; this condition is called peripheral neuropathy.
Peripheral neuropathy can cause tingling, burning, pain, or numbness in the affected areas.
The pain of peripheral neuropathy is difficult to control, though some find topical products that contain capsaicin to be helpful.
Prescription products that may help alleviate the pain caused by peripheral neuropathy include a variety of antidepressants and anticonvulsants.
Improving your blood glucose control may help to restore feeling if your feet or hands are numb.
If you have neuropathy in your feet, check your feet every day for breaks in the skin, areas of redness, or anything else that looks or feels unusual. Report any problems to your doctor promptly.
When neuropathy affects nerves in the body that regulate automatic functions, such as digestion or blood circulation, it's called autonomic neuropathy.
Probably the best-known sign of autonomic neuropathy is erectile dysfunction (ED), but it can also cause:
  • Diarrhea
  • Orthostatic hypotension, or a drop in blood pressure when rising from lying down or sitting
  • Sexual dysfunction in women
  • Slowed stomach emptying, resulting in indigestion and erratic blood sugar control
  • Difficulty starting to urinate or emptying the bladder completely
  • Sweating abnormalities
Treatment options depend on the area of the body affected.

Nephropathy (Kidney Disease)

In diabetic nephropathy, the nephrons (or filtering units) in the kidneys become damaged from chronic high blood sugar.
High blood pressure compounds the problem, and high cholesterol appears to contribute to it as well.
In the early stages of diabetic nephropathy, you may not notice any symptoms, but standard blood and urine tests can detect early signs of dysfunction, and early treatment can stop or slow its progression.
The ADA recommends that all people with type 2 diabetes have a microalbumin test — a urine test that measures the level of the protein albumin in the urine — at diagnosis and annually thereafter to look for kidney dysfunction.
However, because the microalbumin test misses some cases of reduced kidney function, the ADA also recommends that all adults with diabetes have a second kidney function test, the estimated glomerular filtration rate (eGFR) test, at least once a year.

Symptoms of diabetic nephropathy typically appear in the later stages of the disease and often include swollen ankles, fatigue, and elevated blood pressure.