Stretch marks specifically refers to the abdomen during pregnancy due to the bulge caused by the expansion of the lines, so the thigh root for the expansion of the lines, its occurrence can be related to obesity, puberty development rate is too fast or certain endocrine diseases. 1. Obesity: a short period of rapid obesity of the population, weight gain fast, the skin elastic fiber due to skin overextension loss of function, excessive pulling to form cracks, not to restore the original shape, can be in the inner thighs or buttocks and other locations in the formation of silver-white lines. 2. Adolescent growth and development: adolescent people have physical growth and development or rapid growth, at the same time, the body of the adrenal cortex endocrine exuberance, there are skin elastic fibers and collagen fibers degeneration, the formation of swelling lines in the torso parts. 3. Endocrine diseases: such as Cushing’s syndrome patients, due to hyperadrenocorticism, subcutaneous fat increased in a short period of time, there can be swelling lines. There is no specific treatment for swelling lines, if you feel that it affects your appearance, you can consult a regular hospital doctor for details, and if it is caused by a disease, you can actively treat the original disease.