Thickening of the skin in the palm of the hand may be caused by callus, chronic eczema, ringworm and other diseases. 1. Callus: localized skin thickening caused by long-term pressure or friction on the hands, mostly manifested as localized yellow or waxy-yellow, localized thickened plaques, which play a certain protective role on the hands. 2. Chronic eczema: the disease is internal and external multi-factorial inflammatory skin disease, may be related to heredity, environment, allergies and other factors, the patient’s hands will be due to long-term scratching and other hypertrophy, roughness and other changes, and then manifested as the phenomenon of thickening of the skin in the palm of the hand. 3. Tinea versicolor: the superficial fungal infection of the skin of the hand due to dermatophytes causes thickening of the skin of the palm of the hand, especially keratinized tinea versicolor, with thickening of the keratinization of the hand as the main cause. It is recommended that patients with thickened skin on the palms of their hands go to a regular hospital in time, and after a clear diagnosis under the guidance of the doctor, according to the patient’s specific condition, take targeted treatment.