There is no such thing as a sudden widening of the hips, but widening of the hips may be caused by genetics, obesity, childbirth and other reasons. 1. Heredity: If parents have flat hips and wider hips, they may be affected by genetic factors and their offspring will also have wider hips. 2. Obesity: excessive consumption of protein-containing and high-fat foods in daily life may lead to accumulation of fat in the body, resulting in obesity and widening of the hips. 3. Childbirth: During pregnancy, the level of estrogen and progesterone of the patient will rise sharply. This may cause the pelvis and ligaments to relax to facilitate the delivery of the fetus, which may also lead to the phenomenon of widening of the hips. Hereditary crotch width is generally difficult to improve, but for crotch width caused by obesity, childbirth and other factors can be relieved through exercise, massage and other ways. If discomfort occurs, you should go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying your condition.