The common causes of white nose hair in people around 40 years old include physiological factors and pathological factors (such as malnutrition, vitiligo, etc.), as follows: 1. physiological factors: under normal circumstances, with age, the body’s tissues and organs will gradually aging, melanocyte synthesis of melanin function will also decline, if the synthesis of melanin is insufficient, often hair whitening can occur, can be a symptom of the whitening of the nose hair. 2. Pathological factors: (1) malnutrition: if due to dieting, picky eating, partiality and so on, resulting in long-term intake of nutrition within the body is not balanced , will cause malnutrition, easy to affect the normal function of melanocytes, resulting in reduced melanin synthesis, there may be hair whitening phenomenon. (2) Vitiligo: The cause of vitiligo is unknown, and may be related to autoimmune factors, genetic factors, neurochemicals and other factors. Patients usually show skin as well as mucous membranes in the pigmentation loss patches, at the same time, hair can also become white, so vitiligo inside the nasal cavity can appear the phenomenon of whitening of nasal hair. In the case of exclusion of physiological reasons, it is recommended that patients go to the regular hospital dermatology, clear diagnosis and follow the doctor’s instructions reasonable treatment.