Symptoms may include:

• a red line on the skin - demarks the border of the affected tissues
• dry gangrene may cause some pain
• the area becomes cold, numb, and pale and then changes to a brown color and finally black
• dead tissue falls off

If bacterial toxins are allowed to spread in the bloodstream, the other symptoms may include:

• fever
• rapid heart rate
• rapid breathing
• altered mental state
• loss of appetite
• diarrhea
• vomiting
• vascular collapse

Causes may include:

• chronic diseases
• post-traumatic and/or post-surgical causes

Types include:

• dry - arteries become obstructed and the tissue slowly dies because it does not receive adequate blood flow
• moist - occurs in the toes, feet or legs after an injury or some other factor that causes blood flow to stop
• gas - moist gangrene usually caused by a bacteria that produce gasses and toxins as they grow