Symptoms of Gangrene
The symptoms of gangrene vary according to the type of gangrene (wet or dry), the anatomic location (external versus internal sites), and which organ system(s) are affected.

Dry gangrene often begins with the affected area first becoming numb and cool. Discomfort levels vary with the patient's perception. The local area (for example, toe or finger) then starts to discolor, usually turning from reddish to brown and eventually black. During this time, the local area shrinks, becomes dry (mummified), and may slough off the body. Dry gangrene caused by immediate loss of arterial blood supply can first turn pale or bluish and then progress as above.

Wet gangrene, in contrast to dry gangrene, usually begins with swelling and a very painful affected area that may be initially red and show signs of decay (sloughing tissue, pus, local oozing of fluid). Often the fluid and the affected area develop a very bad smell, due to the presence of such foul-smelling compounds as cadaverine and putrescine, which are produced as the infectious agent(s) destroy tissue. This dead and dying tissue develops a moist and black appearance. Additional symptoms that are often seen in patients with wet gangrene are fever and other signs of sepsis such as light-headedness due to low blood pressure.

Internal gangrene, a variant of wet gangrene, has less obvious initial symptoms because the wet gangrene occurs in the internal organs. The patient may be very ill (septic) with gangrene but show few if any visual symptoms that are characteristic for wet gangrene. Occasionally, the skin overlying an organ with wet gangrene may become reddish or discolored, and the area may become swollen and painful. When the surgeon exposes the infected organ, the signs of wet gangrene are apparent. The symptoms vary somewhat according to the organ system infected; for example, patients with gangrene of the bowel due to an incarcerated hernia can have severe pain at the site of the hernia while a gangrenous gallbladder can result in severe pain located in the upper right side of the abdomen.