Merck Manual

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Complications of Diabetes

Complications of Diabetes

Tissue or Organ Affected

Effects

Complications

Blood vessels

Fatty material (atherosclerotic plaque) builds up and blocks large or medium-sized arteries in the heart, brain, legs, and penis.

The walls of small blood vessels are damaged so that the vessels do not transfer oxygen to tissues normally, and the vessels may leak.

Poor circulation causes wounds to heal poorly and can lead to heart attacks, strokes, gangrene of the feet and hands, erectile dysfunction, and infections.

Eyes

The small blood vessels of the retina are damaged, leading to formation of new fragile blood vessels that tend to bleed.

Vision decreases, and ultimately, blindness occurs.

Kidneys

Blood vessels in the kidneys thicken.

Protein leaks into urine.

Blood is not filtered normally.

The kidneys malfunction, and ultimately, chronic kidney disease occurs.

Nerves

Nerves are damaged because glucose is not used normally and because the blood supply is inadequate.

Legs suddenly or gradually weaken.

People have reduced sensation, tingling, and pain in their hands and feet.

The nerves that control internal body processes such as blood pressure and digestion are damaged.

Swings in blood pressure occur (especially when the person stands).

Swallowing becomes difficult.

Digestive function is altered, and sometimes nausea or bouts of diarrhea occur.

Erectile dysfunction develops.

Skin

Blood flow to the skin is reduced, and sensation is decreased, resulting in repeated injury.

Sores and deep infections (diabetic ulcers) develop.

Healing is poor.

Blood

White blood cell function is impaired.

People become more susceptible to infections, especially of the urinary tract and skin.

Connective tissue

Glucose is not used normally, causing tissues to thicken or contract.

Carpal tunnel syndrome and Dupuytren contracture develop.