Gangrene is a serious medical condition in which body tissue dies because of inadequate blood flow, severe infection, or both. The dead tissue may become blackened, shriveled, cold, numb, or foul-smelling and is at risk of spreading harmful bacteria to surrounding areas. Prompt medical assessment is essential: untreated gangrene can lead to systemic infection (sepsis) and death.

Types and key features

  • Dry gangrene results primarily from prolonged loss of blood supply. It often develops slowly in extremities when arteries are blocked by disease or injury; the affected area dries, shrinks and turns dark.
  • Wet gangrene occurs when dead tissue becomes infected. Swelling, blistering and a wet, foul odor are typical; because of active infection it can spread rapidly and is more dangerous than dry gangrene.
  • Gas gangrene is a severe form usually caused by Clostridium bacteria (classically Clostridium perfringens) that produce gas within tissues and toxins that destroy muscle and other structures; it progresses quickly and can be life‑threatening.
  • Internal gangrene affects internal organs such as portions of the intestines, appendix, or gallbladder when their blood supply is cut off or when infection follows tissue death.

For a concise definition of tissue death and related terms see tissue death overview. Clinical descriptions and pathogen information are discussed in resources such as bacterial causes and Clostridium species references.

Causes and risk factors

Gangrene arises from one or a combination of three broad problems: ischemia (insufficient blood flow), infection, and trauma. Common underlying contributors include peripheral arterial disease and atherosclerosis, uncontrolled diabetes, severe frostbite or crush injuries, chronic smoking, and any event that severely damages blood vessels. Conditions that impair immune response or wound healing—such as advanced age, malnutrition or peripheral neuropathy—also increase risk. See clinical risk summaries at risk factors and diabetes-related vascular disease notes at diabetes and circulation.

Signs, diagnosis and distinctions

Early signs vary by type but often include a change in skin color (pale to blue, then brown or black), coldness, numbness, severe pain (initially), and a foul odor if infection is present. Gas gangrene may produce crepitus (a crackling sensation) from gas in tissues. Diagnosis combines physical examination with imaging (x-ray, CT, MRI) to assess the extent and presence of gas, plus laboratory tests and wound cultures to identify infectious organisms. For comparisons between types and clinical guidelines, consult ischemia causes and infected wound management.

Treatment and emergency management

Gangrene is a medical emergency. Treatment depends on type and severity but commonly includes surgical removal of dead tissue (debridement) or amputation to prevent spread; broad‑spectrum intravenous antibiotics for infected forms; and urgent revascularization procedures (angioplasty or bypass surgery) when ischemia is reversible. Gas gangrene requires rapid surgery and targeted antimicrobial therapy; adjunctive hyperbaric oxygen therapy can be considered in selected cases to inhibit anaerobic bacteria and support tissue oxygenation. Practical treatment outlines appear in clinical sources such as vascular injury, bacterial infection control, and muscle infection management.

Prevention, prognosis and notable facts

Preventive measures focus on controlling vascular risk factors: managing diabetes, stopping smoking, treating peripheral arterial disease, and taking care of wounds promptly. Early intervention improves outcomes; dry gangrene may be limited if blood flow is restored, while wet and gas gangrene often require aggressive therapy. Historically, before modern surgery and antibiotics, gangrene commonly led to limb amputation and high mortality; modern vascular surgery, antibiotics and critical care have substantially reduced deaths. For practical prevention tips and patient education materials see wound care and public health resources at chronic disease management.

Further reading and clinical resources: tissue pathology overview, infectious causes, internal organ involvement, vascular causes, surgical considerations, wound infection guidance, microbiology basics, Clostridial infections, muscle and soft tissue infection, risk factor overview, diabetes and vascular health.