The death of bone tissue due to a lack of blood supply. Avascular necrosis also is known as osteonecrosis.

Avascular necrosis is associated with long-term steroid use and drinking too much alcohol. It's most common in people between the ages of 30 and 50. The death of bone tissue can lead to tiny breaks in the bone and cause the bone to collapse. The process usually takes months to years.

Early stages may be symptom-free. Eventually, the affected joint may hurt when weight is put on it or when lying down. Pain can be mild or serious and usually develops gradually. Avascular necrosis often affects the hip, but the shoulder, knee, hand and foot also can be affected.

The goal is to prevent further bone loss. Treatment may include physical therapy, surgery and medicines, such as osteoporosis drugs or blood thinners.