Tummy hair is mostly caused by hormonal changes and is usually a normal physiological phenomenon. However, some pathological factors are not excluded that can also lead to a long hairy stomach. When men enter puberty, androgen secretion is strong, may appear on the stomach hair, chest, legs, facial hair symptoms, all belong to normal physiological phenomenon. When women are pregnant, due to changes in the level of androgens in the body, some pregnant women will also appear the phenomenon of long hair on the stomach, but will not affect the development of the fetus. When the hormones gradually return to normal after the birth, the hair will also fall off naturally. When the endocrine function of women is disrupted, the secretion of androgens in the body increases while the secretion of estrogen decreases, the symptom of hair growth on the top of the stomach may occur. In common diseases such as polycystic ovary syndrome, patients may have symptoms of amenorrhea, irregular menstruation and hirsutism. In addition familial, hereditary hirsutism and supra-adrenal hirsutism, such as adrenal tumors, Cushing’s syndrome, congenital adrenocortical hyperplasia may also cause hirsutism resulting in a long hairy stomach, it is recommended to go to the hospital for examination to clarify the cause and treat the symptoms.