Gangrene is a dead tissue because it was not supplied with blood or due to wound infection. It occurs mostly in legs and feet, and can be fatal.
There are two types of gangrene: dry and wet. Dry gangrene occurs when tissues have no oxygen due to insufficient blood supply. The tissue is locally dead; it does not spread out of the affected area. Wet gangrene is rare; it occurs when an existing wound or dry gangrene is infected by a bacterium. This bacterium is most often clostridium, which lives in dead tissue where there is no oxygen and release gas with unpleasant odor. The infection may spread to the surrounding healthy tissues, and may even cause fatal outcome.
The symptoms of gangrene depend on the type. In dry gangrene, the symptoms may develop gradually, but nevertheless, they appear in a few hours, depending on how fast the reduced blood supply occurs. The symptoms (in the legs) are:
- severe pain in the legs and feet
- pale, cold skin, becoming red, then purple, going black in a few days
- loss of sensation
If the gangrene is consequence of infection, additional symptoms may occur, including abscess around the affected area and high temperature. The infection may affect the bloodstream, when severe blood toxicity develops, i.e. sepsis.
The causes of gangrene are:
- reduced or lack of blood supply – in this case, cells can not live without blood and the tissue dies
- infection – if bacteria stay long in the tissue untreated, they take over, while the tissue dies
The risk factors are:
- ischemia of lower extremities
- Raynaud’s phenomenon
- severe injury
- HIV infection
- cancer therapies
- fat-rich diet
The complication of gangrene arises if it left untreated, in which case the bacteria spread quickly to other organs and can be fatal.
There are several things you can do to prevent gangrene. If you have a condition that can cause gangrene, you have to keep your condition under control, have to regularly check of your feet, change your lifestyle (quit smoking, eat healthy food, exercise) to improve circulation, and help yourself to prevent infections.