Since 1995 - Non Profit Healthcare Advice

Complications of Diabetes

Diabetes is the inability of glucose to enter the cells. The result is that the bloodstream has a high amount of glucose and cells are not able to produce energy for the body. When diabetes is not carefully managed by keeping the amount of sugar in the blood at the right level, the resulting high glucose amounts wreak havoc on nearly every organ system in the body.

One of the main contributing factors in some of the complications mentioned are issues arising from problems with the smallest of blood vessels. High concentrations of glucose lead to weakness in their walls, and the combination of bursts in these vessels and the scar tissue created in the healing process can damage the organs which these vessels serve.

Complications of Diabetes can range from sudden, urgent issues to those that develop slowly over the years. These complications include, but are not limited to:


Heart Disease and Stroke

As many as 65% of people diagnosed with diabetes will eventually die of a heart attack or a stroke. Diabetes greatly increases the risk of a heart attack or a stroke in the following ways:


  • By speeding up the process where the walls of the artery malfunction and they get clogged inside (arteriosclerosis)
  • By altering blood cholesterol and fat levels
  • By making the blood more prone to clotting


Diabetics are subject to earlier and more pronounced cases of arteriosclerosis than non-diabetics.

What Happens in the Body

The build-up of plaque and hardening of the arteries associated with this condition make it much easier for one of the following events to occur:

  • Heart attack: a blockage in the blood vessels surrounding the heart preventing oxygen from reaching the cells, killing the heart muscle.
  • Stroke: a blockage to the blood vessels in the brain, preventing oxygen from reaching the brain.


Heart attack and stroke are both emergency conditions. Failure to treat these conditions within minutes can easily lead to death. NetWellness has topics on Heart Disease and Stroke that describe in greater detail the symptoms of these conditions and how they should be treated. If symptoms of either of these conditions are evident, seek emergency care immediately.


Vision Loss and Blindness (Diabetic Retinopathy)

Although not a sudden process, diabetics face a very real threat of vision loss, including blindness, also called diabetic retinopathy. Nearly 50% of diabetics will develop diabetic retinopathy to one level or another.

What Happens in the Body

Over a period of years, tiny new blood vessels grow in the eyes. High concentrations of glucose in the fluid surrounding these blood vessels make them, and existing blood vessels, extremely fragile. Tiny bulges called micro aneurysms can develop around the retina and other areas in the eye.

If these bulges leak or burst, fluid and blood can spread throughout the eye. Blood clots and scar tissue can form in front of the retina, preventing light from hitting the retina, resulting in blindness. The fluid released can cause swelling which blurs vision. This condition progresses from blurred vision in both central and peripheral vision to complete blindness.


There is no treatment for diabetic retinopathy. Damage to the eyes is permanent, however progression of the condition may be slowed. The best way to avoid developing diabetic retinopathy is to prevent glucose from building up the fluid surrounding the blood vessels in the eye. Careful management of glucose levels is the only way to prevent this condition.


Kidney Failure (Diabetic Nephropathy)

Over time, high blood glucose can have a damaging effect on the kidneys. Nearly 1 in 3 diabetics will experience kidney failure.

What Happens in the Body

One of the side effects of high glucose levels is that extra water is pulled into the blood stream. This can significantly increase blood pressure. Other risk factors for Type 2 diabetes, such as obesity, are frequently associated with high blood pressure as well. High blood pressure affects the nephrons or filtering units in the kidneys. Nephrons were initially designed to filter water and certain small waste products from the blood. Sustained blood pressure and abnormally high glucose concentrations gradually make the vessels in the nephrons more porous. Over time amino acids and proteins are able to escape into the urine through these pores, which is an indication of kidney dysfunction that may eventually lead to kidney failure.


There is no treatment for diabetic nephropathy. Damage to the kidneys is permanent, but progression of the condition may be slowed by careful management of glucose levels and reduction of high blood pressure. In the end stages, swelling will occur in the legs and the patient will require dialysis or a kidney transplant to survive. Untreated, it will result in the body poisoning itself with its own waste products. 


Amputation (Diabetic Neuropathy)

Neuropathies, or areas of nerve damage, are unfortunately common in diabetics. Diabetic neuropathies are caused by a combination of the direct effects of high glucose concentrations and the secondary effects of those high glucose levels on the blood vessels that provide nutrients and oxygen to the nerves.

Neuropathies can affect every organ system in the body, causing the patient to loose sensation or control in the affected area. Most commonly, and perhaps most importantly, feeling is lost in the extremities, commonly the arms and the feet.

What Happens in the Body

Frequently, diabetics will feel a numbness, tingling, or burning sensation in their feet. Poor circulation combined with a lack of feeling makes it very easy for a diabetic to injure his or her foot and not even realize it. Cuts or blisters can easily turn into decubitus ulcers, also known as pressure sores or bed sores, which become infected and have difficulty healing.

Complications of ulcers and sores

An open sore such as an ulcer leaves the body vulnerable to:

  • Cellulitis: a painful infection of the connective tissue in the skin

  • Gangrene: rotting flesh that frequently results in amputation

  • Sepsis: an infection spreading to the blood stream and other organs causing rapid shock and widespread organ failure



Sores of this kind need immediate treatment or they may result in the loss of a foot, leg, or even the life of the patient. NetWellness has a topic on Amputation that provides more information about the issues surrounding amputation.


Diabetic Ketoacidosis (DKA)

Diabetic Ketoacidosis (DKA) is a very dangerous complication of Diabetes. DKA is usually associated with Type 1 diabetes, although, it can also occur rarely with Type 2 diabetes.


Symptoms of DKA often include:


Other symptoms that are sometimes associated with this condition include:

What Happens in the Body

When glucose isn’t able to enter the body’s cells, the body is unable to produce energy. When your body has no other energy sources, it will turn to digesting proteins (muscles) and fats for energy. Muscles will break down their own proteins, releasing amino acids, the building blocks of protein, into the blood stream. When the amino acids reach the liver they are converted to glucose.

For a person whose pancreas functions like it’s supposed to, the glucose produced by the liver would trigger the pancreas to release insulin and let the glucose into the body’s cells to produce energy. But for someone whose pancreas doesn’t work right, all the liver is doing is dumping more sugar that’s not needed in the bloodstream.

Unfortunately, the liver doesn’t realize that there is already too much glucose in the blood because it doesn’t test glucose levels like the pancreas does. The liver tests for insulin. When insulin is not being produced, the liver is tricked into thinking the body is starving and needs more sugar. The liver will create more and more glucose as muscle is broken down. This has catastrophic effects.

When the body is in starvation mode, the liver also digests fats. This produces ketones which provide energy to feed the brain and the heart. This is done as a last ditch effort to remain alive. The brain prefers these ketones as an energy source, instead of the dangerous and plentiful glucose. Because the brain and heart aren’t using up any glucose, the levels of glucose continue to rise.

This is when the situation can become dangerous. With such a high amount of glucose outside the cells, and a decreasing amount inside the cells (since it’s been used for energy), the water in the cells is forced out of the cells in an attempt to even out the amounts of glucose. This causes rapid dehydration and the body tissues begin to collapse as they lose water. Then the kidneys go to work filtering out all of the excess water, which is what causes the frequent urination. In the process, many essential compounds, such as sodium ions, are flushed out in the urine. The loss of sodium causes many cells to have difficulty functioning properly and eventually cells begin to die.


Diabetic ketoacidosis is an emergency condition. Care must be given rapidly. Initially, treatment will focus on re-hydration. Insulin will be gradually re-introduced to the body. Left untreated, ketoacidosis is fatal.


Diabetic Coma (Non-ketotic coma)

Diabetic coma is a due to dehydration caused by high sugar levels caused by untreated or poorly managed diabetes.

“Non-ketotic” means that this condition is not the same as Diabetic Ketoacidosis (DKA). Often the pancreas is still producing insulin, but either not enough or the cells don’t respond to it.


Symptoms of diabetic coma include:

What Happens in the Body

When there is a lot of glucose surrounding a cell and not much glucose inside, and glucose cannot cross into the cell, water moves out of the cell to try to create an equal amount of glucose on both sides. When a diabetic’s glucose level rises very high, the glucose in the blood pulls a large amount of water out of the cells.

Instead of re-entering the cells, the kidneys filter out this excess water and it is excreted in the urine. A combination of dehydration and lots of glucose accumulating in the fluid surrounding brain cells can make it difficult for the brain to function normally. This can lead to coma – a semi-conscious state.


This is another emergency condition. Failure to treat this condition can easily lead to death. If the above symptoms are exhibited, the diabetic should seek emergency care immediately. The goal of treatment is to reverse the dehydration, which will improve the blood pressure, urine output, and poor circulation. Fluids and potassium are replaced by intravenous therapy. High glucose levels are treated with intravenous insulin.

Hope Through Research – You Can Be Part of the Answer!

Many research studies are underway to help us learn about eye diseases. Would you like to find out more about being part of this exciting research? Please visit the following links:

More features about Diabetes:

For more information:

Go to the Diabetes health topic.