Before I discuss complications of diabetes I would like to stress one point. In fact, I think this is the most important point I could ever make about diabetes:

Complications from diabetes are not inevitable!

Long gone are the days when if you had diabetes it meant it was just a matter of time until you lost your eyesight, went on dialysis or had a foot amputated. Thank goodness times have changed! Yet I still not infrequently see people with newly diagnosed diabetes who have vivid memories of older relatives who had diabetes and then had these or other complications, and have the mistaken impression these complications will inevitably happen to them, too. The truth of the matter is that with modern therapies most complications - including the ones I discuss on this page - are avoidable.


For all intents and purposes when we talk about diabetic eye damage we are talking about injury to the back surface of the eye called the retina and in particular, the small blood vessels located there. When retinopathy first starts, these tiny blood vessels become swollen, and they leak a little fluid into the center of the retina. The person's sight usually isn't much affected by this (The absence of symptoms does not mean that "everything must be okay"-hence the need to have regular eye doctor appointments). This condition is called background (or nonproliferative) retinopathy. Often things never progress beyond this stage. But, if they do, the next stage is when tiny blood vessels grow out and across the eye. This is called neovascularization. The vessels may break and bleed into the clear gel that fills the center of the eye, blocking vision. Scar tissue may also form near the retina, pulling it away from the back of the eye. This stage is called proliferative retinopathy, and it can lead to impaired vision and even blindness. The images below (click to enlarge) detail the stages of eye damage as seen by a doctor looking into your eyes with an ophthalmoscope:

Normal Retina

Non-proliferative retinopathy 
 the small red dots are early, swollen blood vessels ("microaneurysms") and small hemorrhages td>

Proliferative Retinopathy 
Proliferative Retinopathy note the fine network of abnormal blood vessels (most aparent in the upper left)
Proliferative Retinopathy-advanced 
a large hemorrhage is present

These are things you can do to avoid eye damage from diabetes:

  • Strive to achieve and maintain target blood glucose levels (before meals 4-7, two hours after meals 5-10, A1C 7 or less)
  • Keep your blood pressure under 130/80.
  • Keep your LDL cholesterol 2 mmol/L or less.
  • Don't smoke.

(One other important point. If someone has had very poor blood sugars and their sugars are then brought rapidly down to normal, it changes the way the light bends through the lens of the eye. And that causes blurred vision. This corrects over a few weeks. So if you have newly diagnosed diabetes and, after being started on treatment you find your vision to have suddenly become blurry, this is often, believe it or not, a good means your sugars are on they way down. Incidentally, don't waste your money on expensive prescription glasses the day you get diagnosed as having diabetes. Buy some cheapo pair off the shelf for a few bucks. Once your sugars have been stable for a few weeks, your vision will likely return to its usual state and then you can determine if you truly need some expensive prescription glasses.).

Heart Disease (Coronary Artery Disease)

Coronary artery disease is a build-up of cholesterol in the walls of the arteries that feed the heart muscle with oxygen. if the blockage is severe enough it leads to a heart attack.

You can avoid coronary artery disease (and hence, a heart attack) by:

  • Eating heatlhfully
  • Exercising regularly
  • Weight control
  • Keeping your LDLcholesterol 2 mmol/l or less
  • Keeping your blood pressure under 130/80
  • Not smoking
  • Keeping your blood glucose levels well controlled:  (before meals 4-7, two hours after meals 5-10, A1C 7 or less)
  • If you are at high risk of a heart attack, taking statin and ACE inhibitor or ARB medications
You can discover more about how to avoid heart diseae here.

Kidney Failure

As most people know, the kidneys "purify" the blood by removing certain waste products. (They also do a whole bunch of other esential things like controlling salt and potassium blance, influencing red blood cell production, regulating blood pressure, and more).

You can avoid kidney failure by:

  • Keeping your blood glucose levels in target
  • Keeping your blood pressure in target
  • Taking an ACE inhibitor or ARB medication if you are known to have any degree of kidney malfunction

Erectile Dysfunction

Many men with diabetes develop erectile dysfunction. As anyone who has turned on a TV any time in the past few years knows there are several medications (Cialis, Levitra, Viagra) available to treat this condition. And, if one of these pills doesn't do the trick other therapies - including injecting a special type of medicine into the penis, using a special vaccuum device, or having an implant are other options.

Peripheral Neuropathy

Peripheral neuropathy is nerve damage in the feet. This typically is felt as numbness, burning, or shooting pains. The pain can vary from being minimal to being severe.

There are many different types of medicine available to lessen the pain of neuropathy including Neurontin, Lyrica, and amitriptyline.

If you have neuorpathy then you are increased risk of developing foot ulcers. Therefore, you must carefully inspect the bottoms of your feet daily and, if you are unable to, then have someone else do this for you. Also, if you have neuropathy, have your toenails trimmed by a foot care professional, don't do it yourself.