One side of the nipple itchy consider may be life and behavioral factors, such as inappropriate intimate clothing, toiletries, etc.; or in a special physiological period, resulting in increased secretion of sex hormones, or during pregnancy, lactation due to milk secretion to produce itching; and pathological factors, such as breast eczema, nippitis, mastitis, nipple eczema-like breast cancer, etc. I. Life and behavioral factors 1. inappropriate intimate clothing: due to long-term friction or poor material of intimate clothing, resulting in skin allergy, nipple itch, there will also be one side of the nipple itch; 2. inappropriate toiletries: some toiletries such as soap, shower gel, etc. can trigger skin allergies, triggering one side of the nipple itch. Second, physiological factors are mainly seen in female patients in special periods such as menstruation and puberty, due to the increased secretion of estrogen and progesterone, which may stimulate the nipples, making them more sensitive and thus producing itchy sensations. Pregnancy, lactation due to milk secretion may also produce itchy sensation, the side of the nipple itchy. Third, the pathological factors 1, breast eczema: can make patients on one side of the nipple and around the areola to produce itching, cracking, heavy vesicles, oozing, moist and well-defined patches, the formation of the disease is more complex, including external environmental stimuli, mental factors or the presence of chronic infectious lesions, etc.; 2, nippleitis: nipples with skin breakdown, Staphylococcus aureus or other bacterial entry may This can lead to itching, redness and swelling of one side of the nipple, which may also be accompanied by a stinging sensation; 3, mastitis: mainly seen in female patients, lactating women are mostly due to milk stagnation, secondary to bacterial infection, non-lactating women produce the disease may be related to milk duct obstruction, infection, breast trauma and other factors, all of which can make patients appear itching on one side of the nipple, which can also be accompanied by swelling and pain, oozing 4. Eczema-like breast cancer: one of the typical symptoms of this disease is itching and burning sensation on one side of the nipple, and as the disease develops, the skin of the nipple and areola will gradually become rough, vesicular like eczema, and form ulcers. For patients whose symptoms do not improve after eliminating the causative factors, it is recommended to go to breast surgery for examination as soon as possible to exclude the possibility of breast cancer and then treat the disease.