The white block on the hand may be stimulated by compression and extrusion of the hand, resulting in poor local blood circulation, which in turn results in pale, bloodless color of the hand. It is recommended that patients have appropriate massage or hot compresses to promote blood circulation, and the white block can disappear quickly. If the white block is not caused by poor blood circulation, it is indeed a skin discoloration, which may be post-inflammatory hypopigmentation spot, or may be senile white spot, white pity, vitiligo. 1, post-inflammatory hypopigmentation spot: after local inflammation of the skin, the basal layer melanin is reduced, and melanin vesicles are also reduced, which will cause local skin hypopigmentation, resulting in white block; 2, senile white spot: one of the manifestations of skin aging. Common in people over 50 years old, mainly on the skin of the chest, back, abdomen, etc., some people can also appear on the hands, usually rice grain to green bean size round white spots, slightly depressed, the number varies, often increases with age, without any conscious symptoms, can be without treatment; 3, white pityriasis: also called simple pityriasis, belongs to a kind of dermatitis, characterized by thin bran-like scaly hypopigmented spots, performance For skin hypopigmented spots, namely white blocks, the number is single or multiple, size varies. White furuncle can be self-healing, no need for treatment, can be localized with mild emollient cream, but the recovery time is variable, most patients can recover within 1 year; 4, vitiligo: is a common acquired pigment loss skin mucosal disease, clinical performance white spot single, distribution or generalized, lesion size varies. The patient often has no conscious symptoms, and the progressive stage can be accompanied by itching. It can be treated with glucocorticoid agents or calcium-regulated phosphatase inhibitors, such as dexamethasone, hydrocortisone, tacrolimus, pimecrolimus, etc.