The common causes of short legs can be divided into growth and development factors and pathological factors, of which pathological factors include: scoliosis deformity, lower limb fracture, hip dislocation, congenital hip dysplasia and so on. 1. Growth and development factors: normal people have rapid development of both lower limbs, but most people have some differences in the length of the two legs, which is a normal physiological state, if it does not affect daily activities, there is no need to intervene or treatment. 2. Scoliosis: Scoliosis can cause tilting of the pelvis, resulting in the appearance of long and short legs. Mild scoliosis can be corrected with traction therapy, while severe cases require surgery. 3. Lower limb fracture: As a result of lower limb fracture, the affected side of the leg is shorter than the healthy side, which leads to short and long legs. If the fracture occurs, it should be promptly fixed and repositioned to avoid deterioration of the condition and damage to other tissues. 4. Hip dislocation: Hip dislocation often occurs in car accidents or high violence injuries, so that the head of the femur is dislocated to the front, back and center, and after the dislocation, the healthy side of the leg is longer than the affected side, resulting in the long and short legs. Hip dislocation is often multi-trauma, so while reset treatment, other parts of the injury should be treated at the same time for symptomatic treatment. 5. Congenital hip dysplasia in children: it is a general term for structural abnormality of the hip joint in infancy or childhood, which has a greater impact on children’s health, and can be manifested as asymmetry of the thighs or calves, with the affected side becoming shorter and thinner, resulting in long and short legs, which is recommended to be handled in the early stage of the disease. If it is due to growth and developmental factors, there is no need for treatment. If it is due to pathological factors, it is recommended to consult a doctor immediately for symptomatic treatment to avoid worsening of the condition.