If the blood supply to a body part is cut off, the tissue can die and become black. This is called gangrene, and in the worst case, limbs must be amputated.
With so-called dry gangrene, the tissue dies due to a poor blood supply. With wet gangrene or cold fire, the tissue is affected by rotting bacteria.
If the blood supply and thus the oxygen supply to tissue decreases or disappears completely, for example due to injury or an infection, the tissue may die. Then it becomes black.
We then speak of gangrene, of which there are two variants: with and without bacteria.
1. Blood supply stagnates
Narrowed blood vessels
If blood does not flow to, for example, a foot and the body part is therefore not supplied with oxygen and nutrients, the tissue can die off in a few days to a few months.
The blood supply can be cut off by injury, an infection, a disease such as diabetes or a blood clot in an artery.
- Pain falls away after nerve tissue dies off
Dying tissue is extremely painful in the beginning, but the pain disappears as the nerve tissue also dies.
The skin slowly turns blue, and when the fabric is completely dead, it becomes black and leathery. It dries out and becomes 'mummified'.
3. Amputations save the rest© KEN IKEDA MADSEN
The gangrene usually starts in the toes, which can fall off, and crawls up along the leg.
If doctors arrive early enough, vasodilator drugs can restore blood flow to the dying area, but amputating the foot is often the only option.