Very rough and hard hands can be caused by physiological factors, but also by toad skin disease caused by vitamin A deficiency and pellagra caused by niacin deficiency. General treatment and vitamin A and other medications can be taken. 1. Physiological factors: some patients due to physical factors or often do rough work, tired work, hand friction is more frequent, there can be physiological skin horny layer hyperplasia, which leads to the phenomenon of very thick and hard hands. General attention to moisturizing, reduce physical activity and friction can be improved. 2. Toad skin disease: generally refers to the dry and rough skin caused by vitamin A deficiency, can appear pimples, night blindness, corneal dryness and other symptoms. In the skin, the main manifestations are dry skin, easy to flake, epithelialization hyperplasia, reduced perspiration, keratinization congested hair follicles and so on. Oral vitamin A can be improved. 3. Pellagra: At first, it manifests as erythema, similar to sun spots, with burning and itching sensation. Subsequent oozing, the formation of herpes and blisters, and then scabs, hyperpigmentation, the skin becomes rough, can be manifested as a hand is very rough and hard. Niacin or niacinamide taken orally may improve. Rough and hard hands may also be caused by other reasons such as eczema, it is recommended to consult a doctor in time to find the cause, under the guidance of the doctor’s scientific treatment.