Boys waist and knee soreness and weakness of the limbs, summarized as three reasons: first, life; second, physiology; third, pathology. 1, life: after the boys have sex, overindulgence, such as the normal 2-3 times a week sex, and more than 2-3 times a week frequency called overindulgence. Excessive loss of kidney essence, too much sex, it will lead to premature aging, and gradually it will cause the waist muscle soreness and weakness of the limbs, which is life. 2, physiology: the kidney is the innate essence, the kidney main bone marrow, healthy waist, when the innate deficiency, kidney essence deficiency, the main bone marrow, healthy waist function will decline, the waist and knee soreness and weakness of the limbs. 3, pathology: often stay up late, drinking alcohol, smoking, irregular life, have bad habits, and often take drugs, the kidney essence damage, the same will lead to kidney weakness, kidney weakness, a long time will also form the waist and knee weakness, limb weakness. According to the different situations to categorize, if it is just life, you have to abstain from life, if it is physiological and pathological, you have to seek timely treatment from a doctor.