18 years old chest has sagged, can improve the dietary structure, moderate upper limb exercise, wear appropriate underwear, surgical treatment, etc.. 1. Improve the diet structure, usually eat more protein-rich food, try to eat less high fat, greasy food, high protein food can increase the elasticity of muscle fibers, improve the symptoms of flaccidity. 2. Adequate upper limb exercise, usually more exercise, pay attention to weight loss, especially increase the upper limb exercise, can improve local muscle strength, improve sagging. 3. Wear suitable underwear, this age breast ptosis, most of the mammary gland development is better, you can wear suitable underwear, to improve the symptoms of ptosis. 4. Surgical treatment: including implant filling, autologous fat transplantation and other ways. However, it is generally not recommended for patients, unless breast ptosis has already had serious physical and mental effects on the patient. Most of them can get better by adjusting their life and diet, and if necessary, go to the hospital for consultation.