Gangrene is the name for dead, deoxygenated tissue. The characteristic black color is a sign that skin and (often) the muscle and bone below it are dead. There are two basic forms of gangrene: dry and wet.
Dry gangrene is not a consequence of bacterial infection, but the blood supply to some tissues is simply interrupted or reduced. This may be due to arterial embolism, poor circulation due to diabetes or arteriosclerosis, and often frostbite. The area deprived of oxygen is dead, but the gangrene does not spread beyond that area.
Tissue deprivation is painful. When the tissue dies, the sensation is lost and the tissue gradually turns black. A visible line marks the boundary between dead and live tissue.
In the UK, only one in 25 000 people dies from dry gangrene annually. However, since the dead tissue is not resistant to infection, there is always a risk that this form of gangrene will cause humid gangrene or blood poisoning.
What to do?
If you have one of the disorders that can lead to dry gangrene, you can undertake a series of precautions. Do not smoke. If you have diabetes, hold it under control. If you think you can get a dry gangrene, contact your doctor immediately.
The doctor will try to improve blood circulation in the affected area by various measures before it is too late. Anticoagulants or vasodilators may be useful, but it is also advisable to have a surgical procedure that unclogs the artery.
If the gangrene gets infected, you will get antibiotics to prevent the development of wet gangrene. If dry gangrene does not respond to treatment, the amputation of the affected part is inevitable. It is also necessary to remove part of the live tissue together with the affected area.
If this is not done, the blood disorder, which has caused the gangrene, can prevent complete healing after surgery.