Body odor, may be caused by physiological reasons, such as daily personal not pay attention to hygiene, etc.; may also be caused by pathological reasons, such as armpit odor, some internal diseases. 1. Physiological reasons: the most common ones are not paying attention to hygiene, especially for some men, who are more active in daily life. If they don’t bathe or wash their clothes frequently, the bacteria will multiply excessively and decompose their sweat, which may cause bad odor. 2. Pathologic factors: (1) Armpit odor: usually due to the sweat secreted by the sweat glands located in the perineum, armpits and other parts of the body, which has a high content of fatty acids, and after decomposition by bacteria, an unsaturated fatty acid is formed, which produces a foul odor. (2) some internal diseases: such as diabetic patients, due to the serious lack of insulin and metabolic disorders, diabetic ketoacidosis occurs, resulting in its exhaled with rotten apple flavor of the gas; also such as organophosphorus poisoning, the patient can exhale garlic flavor of the gas. These two diseases will not only make the patient’s body odor, but also life-threatening, it is recommended to seek medical attention. Body odor may also have other reasons, it is recommended that patients go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.