Armpit hair has turned white considering that it is caused by aging or diseases such as vitiligo and armpit hair ringworm. 1. Ageing: With age, the human body will naturally age, and may appear hair, eyebrows, armpit hair and other body hair become white, is a normal situation. 2. Vitiligo: Vitiligo is caused by the destruction of melanocytes, which is mainly manifested as white spots, and if it occurs in the armpits, it may also happen that the armpit hair becomes white. 3. axillary lichen planus: axillary lichen planus is a bacterial infection of the superficial stratum corneum of the axillary hair caused by bacillus rodentium, the hair dry nodules is the main clinical symptom of axillary lichen planus, with the progress of the disease, the affected area will also appear hair dry, loss of luster, and whitening and so on. There are many reasons for the whitening of armpit hair, so it is recommended that the patient consult a doctor for a clear diagnosis.