Gangrene is the death of tissue, often resulting from an obstruction in the blood supply to the tissue. The blood that feeds your tissues provides oxygen, nutrients that feed your cells and immune system, without a proper blood supply, your cells can't survive. Gangrene most commonly affects the extremities, including your toes, fingers and limbs, but can also occur in the muscles and in internal organs.

Three Major Types of Gangrene:

a. Dry gangrene is a condition that results when one or more arteries become obstructed, in this type of gangrene, the tissue slowly dies because of inadequate or no blood supply. This occurs mostly in the extremities and it may develop in people with diabetes or advanced hardening and narrowing of the arteries. It may also develop after prolonged exposure to freezing temperatures.

• Symptoms: In dry gangrene, the tissue first becomes bluish and they feel cold to the touch. As time progresses, a line of demarcation appears between the healthy and devitalized tissue, which becomes dry and black. Eventually, there may be a separation of the dead tissue from the living tissue, with spontaneous amputation of the involved extremity. If the gangrene does not affect an entire extremity, the gangrenous area may separate and slough off, leaving an ulcer in the skin.
• Treatment: Treatment of this type of gangrene is aimed at improving circulation to the affected area. This may be accomplished with drugs or through the surgical removal of the obstruction.

b. Moist, or wet, gangrene is caused by certain bacterial infection. It can develop following a severe burn, frostbite or injury. When blood flow stops, bacteria begin to invade the muscle and thrive, multiplying quickly without interference from the body's immune system. It often occurs in people with diabetes who unknowingly injure a toe or foot.

• Symptoms of Moist or Wet Gangrene: The affected area becomes swollen, discolored, and often foul smelling.
• Treatment: Administration of antibiotics and sometimes the surgical removal of the dead tissue to keep the infection from spreading.

c. Gas gangrene is an infection caused by certain bacteria of the genus Clostridium. These bacteria live in the soil and thrive in an atmosphere that is low in oxygen. The huge majority of gas gangrene cases occur as complications of bad wounds, particularly ones that are contaminated with dirt.

• Symptoms: After an incubation period of one to four or five days, the affected tissue is swollen, painful and cold. A watery, brownish, foul-smelling fluid drains from the wound, and little bubbles of gas develop in the tissues.

• Treatments: Gas gangrene is often treated with the antitoxin for clostridium. In a number of cases, amputation may have to be used to keep the infection under control. Severe cases have been treated by keeping the patient in an oxygen-rich atmosphere, as in a hyperbaric chamber. In hyperbaric oxygen (HBO) therapy the patient is placed in a pressurized chamber and receives 100% pure oxygen to breathe. This has been shown useful in inhibiting the production of toxins in gas gangrene and for getting oxygen quickly to tissues.

Other Less Common Type of Gangrene:

d. Internal gangrene this type of gangrene can affect one or more of your organs, most commonly the intestines and gallbladder.

e. Fournier's gangrene is the most rare type of gangrene, it involves the genital organs. Men are most often affected, but women can develop this type of gangrene as well. This usually occurs due to an infection in the genital area or urinary tract. Symptoms includes; genital pain, tenderness, redness and swelling.

Other Treatment:

Chelation therapy is a treatment which uses an intravenous solution containing the drug ethylenediamine tetra-acetic acid (EDTA), among other substances. In the bloodstream, EDTA binds and removes toxins and plaque formation on arterial walls. It therefore promotes circulation throughout the body and may help reverse the processes leading to gangrene.