Exams and Tests

The diagnosis of gangrene is based on history, physical examination, blood tests, and other exams.

The health-care provider asks the person about any history of injury, chronic diseases (such as diabetes), surgery, cigarette smoking, and exposure to extreme cold.

Physical examination of the affected area is performed to look for signs of gangrene.

Blood test results show an increase in the number of white blood cells in persons with wet gangrene.

A sample of the drainage from the wound is examined to identify the bacteria causing the infection.

An x-ray film may be performed to examine the affected tissue for the presence of gas bubbles.

Imaging studies, including a CT scan and/or MRI, can help determine the extent of damage to the tissues and the amount of gas present.

In people with dry gangrene, an arteriogram may be performed to visualize any obstruction in the artery which supplies blood to the affected part.