Femoral head necrosis: also known as aseptic or ischemic necrosis of the femoral head, is one of the common bone and joint diseases. Causes: The causes of femoral head necrosis are diverse and complex, and the common causative factors are as follows: 1, trauma: such as femoral neck fracture, hip dislocation, hip joint sprain and contusion, etc. 2, hormone: long-term use of large amounts of hormones or excessive daily amount, dose increase or decrease mutation, etc. 3, alcohol stimulation: the accumulation of alcohol in the body due to long-term heavy drinking, resulting in increased blood lipids and liver function damage. Elevated blood lipids, resulting in increased blood viscosity and slowed blood flow, resulting in changes in blood coagulation, leading to blockage of blood vessels or fat embolism, resulting in osteonecrosis. 4, osteoporosis: contributes to osteonecrosis. 5, post-surgical necrosis: in the clinic after internal fixation of femoral neck fracture, after vascular grafting and other and osteonecrosis. Symptoms: 1. Pain: The pain can be intermittent or continuous, aggravated by walking activities, sometimes for rest pain. The pain is mostly pins and needles, dull pain or soreness and discomfort, often radiating to the groin area, inner thigh, posterior hip and medial knee. 2. Joint stiffness and difficulty in movement: the affected hip joint has unfavorable flexion and extension, difficulty in squatting, inability to stand for a long time, and duck walk. 3.Crippling: progressive short limp, due to hip pain and femoral head collapse, or late onset of hip subluxation. Intermittent claudication often occurs in the early stage. Prevention: 1, must strengthen the awareness of self-protection of the hip. 2.When walking, especially the elderly should pay attention to their feet and be careful of falling, especially in winter when walking on snow and ice. 3, hip injuries should be treated in a timely manner, do not walk too much before the injury is healed, so as to avoid repeated injuries. 4, try not to use or use less hormone drugs. 5, because of related diseases must be applied hormone, should master the principle of short-term appropriate amount, and with the expansion of blood vessels, vitamin D, calcium, etc., do not disobey the doctor’s advice, abuse hormone drugs. 6, should change the bad habits of long-term alcohol abuse or quit drinking. 7, diet should be done: do not eat too much chili, do not drink too much alcohol, do not take hormone drugs, pay attention to increase the intake of calcium, eat fresh vegetables and fruits, more sunshine, prevent weight bearing, regular activities, etc. have a preventive effect on femoral head necrosis.