Explanation and Causes:
Gangrene is a condition that is characterized by the death of an organ or body tissue. It is a very serious condition that requires immediate medical attention.
There are 3 types of Gangrene:

Dry Gangrene
Wet Gangrene
Gas Gangrene

All three of these can be caused by:

Serious injury
Diabetes
Blood vessel disease such arteriosclerosis
Surgery
Infection

Symptoms:
General symptoms [...]