August 2014

Complications of Diabetes

Complications of Diabetes

The most important goal in treating diabetes is prevention of complications. Diabetes is not adequately treated, that is, if blood sugar remains uncontrolled or above 140 mg/dl for prolonged periods of time, can lead to damage of the heart, blood vessels, eyes, kidneys, and nerves. This can happen even if the diabetic does not know damage is taking place. This is why it is extremely important to diagnose diabetes early and treat it effectively. Long-term serious damage can occur if treatment is inadequate even before there are any feelings, signs or symptoms of external illness.
Exactly how diabetes causes these long-term problems is unclear. However, we do know that changes in small blood vessels and nerves are common in poorly controlled diabetes. These changes may be the first step toward the many problems diabetes can cause. Unfortunately, no one can predict which diabetics will develop some or any of these complications, however complications are most likely to occur in individuals who have had poorly controlled diabetes for many years. Since an individual can have diabetes without knowing it, one or more of these complications may be the first sign suggesting that they suffer from diabetes.

Heart Disease

Heart disease is the most common life-threatening disease linked to diabetes, and experts say diabetes doubles a person's risk of developing heart disease. In diabetic heart disease, deposits of fat and cholesterol build-up in the arteries that supply blood to the heart. When this buildup blocks blood from getting to the heart, a potentially fatal heart attack if likely to occur.

Other important risk factors include hypertension (high blood pressure), obesity, high amounts of fats and/or cholesterol in the blood, and cigarette smoking. Eliminating these risk factors, along with adequate treatment of the diabetes, can reduce the risk of heart disease. The American Heart Association can provide you with literature that explains what heart disease is and how to prevent it.

Kidney Disease

People with diabetes are also more likely to develop kidney disease than other group of individuals. The kidneys filter waste products from the blood and excrete them in the form of urine, maintaining proper fluid and electrolyte balance in the body. While an individual can live without one kidney, when both kidneys are damaged a special treatment process, called dialysis, will likely be essential to keep them alive. Most people with diabetes will never develop kidney disease, but proper diabetes treatment can further reduce the risk. High blood pressure also can add to the risk of kidney disease. Therefore, regular blood pressure checks and early treatment of diabetes and other risk factors can help prevent kidney disease.

Urinary tract infections are also an important cause of kidney problems. It is known that diabetes can affect the nerves that control the bladder, when this happens it can make it difficult for a person to fully empty his or her bladder completely. Bacteria can form in the unemptied bladder and the tubes leading from it both up to the kidneys and down to the urethra. This can eventually lead to ascending infection from the bladder up into the kidneys. Symptoms of a urinary tract infection frequently include frequent and/or painful urination, blood in the urine, and pain in the lower abdomen and back. Prompt examination and treatment by a doctor is essential to limit or eliminate the infection. Once a urinary tract infection reaches the kidneys, causing pain, fever,  kidney damage is possible. Antibiotics are generally essential to treat the infection. It is also essential that the diabetic drink large amounts of water or other fluids to cleanse the kidney and maintain the body’s fluid balance.
Kidney problems can cause water retention, or edema, a condition in which fluid collects in the body, causing swelling, often in the legs and hands. If you have swelling, it is essential to determine if this swelling relates to impaired kidney function.

Eye Problems

Diabetes can affect your eyes in several ways. See our special handout Don’t Lose Sight of Diabetic Eye Disease.  Generally, the most common eye problem seen with diabetes occurs early and is caused by  the effects of poor blood sugar control. This is usually blurred vision and is caused by high blood sugar raising the refractive index of the fluids in the eyes. This happens because elevated blood sugar can affect the balance of fluid in the lens of the eye. The lens of the eye works much like a flexible camera lens to focus images. If the lens absorbs more water than normal and swells, its focusing power changes. Diabetes also may affect the function of nerves that control eyesight, causing blurred vision
Initially this condition is temporary and can be corrected with better diabetes control. However, long-term diabetes can cause changes in the eyes that threaten vision. Stable blood glucose levels and yearly eye examinations can help reduce the risk of serious eye damage.
While early blurred vision may only be caused by increased refractive index of the eye, later blurred vision can be caused by other more permanent problems created by the poorly controlled diabetes. Cataracts and glaucoma are eye diseases that occur more frequently in people with diabetes. Cataract is a clouding of the normally clear lens of the eye. Glaucoma is a condition in which pressure within the eye can damage the optic nerve that transmits visual images to the brain. Early diagnosis and treatment of cataract and glaucoma can reduce the severity of these disorders.

Diabetic Retinopathy

Diabetic retinopathy, a disease of the retina, the light sensing tissue at the back of the eye, and is a common concern among people with diabetes. Diabetic retinopathy damages the tiny vessels that supply the retina with blood. The blood vessels may swell and leak fluid. When retinopathy is more severe, new blood vessels may grow from the back of the eye and bleed into the clear gel that fills the eye, the vitreous.
While most people with diabetes may never develop serious eye problems, people who have had diabetes for 25 years are more likely to develop retinopathy. Experts think high blood pressure may contribute to diabetic retinopathy, and that smoking can cause the condition to worsen. If someone experiences blurred vision that lasts longer than a day or so, sudden loss of vision in either eye, or black spots, lines, or flashing lights in the field of vision, a doctor should be alerted right away.
Treatment for diabetic retinopathy can help prevent loss of vision and can sometimes restore vision lost because of the disease.
A yearly eye examination with dilated pupils makes it possible for an ophthalmologist, an eye doctor, to notice changes before the illness becomes harder to treat. Scientists are testing new means of treating diabetic retinopathy.

Legs and Feet

Leg and foot problems can arise in people with diabetes due to changes in blood vessels and nerves in these areas. Peripheral vascular disease is a condition in which blood vessels become narrowed by fatty deposits, reducing blood supply to the legs and feet. Diabetes also can dull the sensitivity of nerves. Someone with this condition, called peripheral neuropathy, might not notice a sore spot caused by tight shoes or pressure from walking. If ignored, the sore can become infected, and because blood circulation is poor, the area may take longer to heal.

Proper foot care and regular visits to a doctor and immediate follow up on any sores or foot pain can prevent chronic foot and leg sores and ensure that any that do not become infected and require antibiotics or amputation. Helpful measures include inspecting the feet daily for cuts or sore spots. Blisters and sore spots are not as likely when shoes fit well and socks or stockings aren't tight. A doctor also may suggest washing feet daily, with warm, not hot water; filing thick calluses; and using lotions that keep the feet from getting too dry. Shoe inserts or special shoes can be used to prevent pressure on the foot.

Diabetic neuropathy, or nerve disease, dulls the nerves and can be extremely painful. A person with neuropathy also may be depressed. Scientists aren't sure whether the depression is an effect of neuropathy, or if it's simply a response to pain. Treatment, aimed at relieving pain and depression, may include aspirin and other pain-killing drugs.

Any sore on the foot or leg, whether or not it's painful, require immediate attention. Treatment can help sores heal and prevent new ones from developing. Problems with the feet and legs can cause life-threatening problems that require amputation-surgical removal of limbs if not treated early.

Other Effects of Diabetic Neuropathy

Nerves provide muscle tone and feeling and help control functions like digestion and blood pressure. Diabetes can cause changes in these nerves and the functions they control. These changes are most frequent in people who have had other complications of diabetes, like problems with their feet. Someone who has had diabetes for some years and has other complications, may find that spells of indigestion or diarrhea are common. A doctor may prescribe drugs to relieve these symptoms. Diabetes also can affect the nerves that control penile erection in men, which can cause impotence that shows up gradually, without any loss of desire for sex. A doctor can find out whether impotence is the result of physical changes, such as diabetes, or emotional changes, and suggest treatment or counseling.

Skin and Oral Infections

People with diabetes are more likely to develop skin infections, like boils and external ulcers, than the average person. Women with diabetes may develop vaginal infections more often than other women. Checking for infections, treating them early, and following a doctor's advice can help ensure that infections are mild and infrequent. Infections also can affect the teeth and gums, making people with diabetes more susceptible to periodontal disease, an inflammation of tissue surrounding and supporting the teeth. An important cause of periodontal disease is bacterial growth on the teeth and gums. Treating diabetes and following a dentist's advice on dental care can help prevent periodontal disease.


Very high blood sugar levels can cause symptoms that are hard to ignore: frequent urination and excessive thirst. However, in someone elderly people or people in poor health, these symptoms may go unnoticed. Without treatment, a person with high blood sugar or hyperglycemia can lose fluids, become weak, confused, and even unconscious. Breathing will be shallow and the pulse rapid. The person's lips and tongue will be dry, and his or her hands and feet will be cool. A doctor should be called immediately.
The opposite of high blood sugar, very low blood sugar or hypoglycemia, is also dangerous. Hypoglycemia can occur when someone hasn't eaten enough to balance the effects of insulin or oral medicine. Prolonged, strenuous exercise in someone taking oral diabetes drugs or insulin also can cause hypoglycemia, as can alcohol.

Someone whose blood sugar has become too low may feel nervous, shaky, and weak. The person may sweat, feel hungry, and have a headache. Severe hypoglycemia can cause loss of consciousness. A person with hypoglycemia who begins to feel weak and shaky should eat or drink something with sugar in it immediately, like orange juice. If the person is unconscious, he or she should be taken to a hospital emergency room right away. An identification bracelet or necklace that states that the wearer has diabetes will let friends know that these symptoms are a warning of illness that requires urgent medical help.

Points to Remember

  • Diabetes can cause long-term complications such as heart, kidney, eye, and nerve disease.
  • Careful treatment of diabetes and checking for signs of complications can lower the chances that someone will be troubled by these conditions.
  • An identification bracelet or necklace stating that the wearer has diabetes can help ensure that friends or strangers won't ignore symptoms that signal a medical emergency.