Gangrene refers to the death of body tissue due to a lack of blood flow or a bacterial infection. Gangrene most commonly affects the extremities, including your toes, fingers, and limbs, but it can also occur in your muscles and internal organs.
Gangrene may occur due to one or both of the following:
Lack of blood supply: Your blood provides oxygen, nutrients to feed your cells, and immune system components, such as antibodies, to ward off infections. Without a proper blood supply, cells can’t survive, and your tissue decays.
Infection: If bacteria thrive unchecked for long, the infection can take over and cause your tissue to die, causing gangrene.
When gangrene affects your skin, signs and symptoms may include:
- Skin discoloration — ranging from pale to blue, purple, black, bronze or red, depending on the type of gangrene you have
- A clear line between healthy and damaged skin
- Severe pain followed by a feeling of numbness
- A foul-smelling discharge leaking from a sore
Source: Mayo Clinic