There are many reasons for the yellowing of the back of the hands, which may be caused by carotenemia, hyperkeratosis of the skin, jaundiced hepatitis and so on. 1. Carotenemia: The yellowing of the back of the hands can also occur due to excessive intake of certain foods, such as carrots, tangerines, oranges, etc., which cause hypercarotenemia, resulting in yellowing of the skin. 2. Excessive skin keratinization: For example, if there is a local callus (callus) caused by obvious friction, or if there is hereditary palmoplantar keratosis, the skin of the hands will show obvious thickening of keratinization, and yellowing of the back of the hands will appear. 3. Jaundice hepatitis: Jaundice hepatitis is usually caused by hepatitis viruses, alcohol, drugs and other factors, after the disease will appear nausea, generalized weakness and other symptoms, accompanied by yellowing of the skin sclera. For the above symptoms, it is necessary to further improve the relevant examination to clarify the specific condition, and then give appropriate treatment.