A thin breast gland means that the gland is diagnosed as having a thin gland when the thickness of the gland is less than 0.8cm during a breast ultrasound. In normal adult women, the thickness of the breast gland is 0.8-1.2cm. If it is lower than 0.8cm, the gland is thin, and if it is higher than 2.0cm, the gland is thickened, but there are individual differences. In women, the gland thickens during lactation and gradually thins after menopause, dropping to a minimum value in old age. The thinness of the breast gland alone, without nodules or other abnormal changes, does not require special treatment and is a normal physiological phenomenon. Some young women with cosmetic tendencies, or women who are in a period of weight loss, can be treated surgically to change the thickness of the breast gland, but it is recommended that everything goes better naturally, or by strengthening exercise and eating more soy foods and seafood to stimulate the breast gland to become thicker.