Possible causes of sudden growth of spots on the wrist include: seborrheic keratosis, flat warts, endocrine disorders, too much ultraviolet radiation, etc., according to the specific situation to identify. 1. Seborrheic keratosis: may be due to viral infection, ageing, hepatitis, etc., can be seen dark brown or light brown plaque. Treatment can be surgical excision, liquid nitrogen freezing, if necessary, to do skin tissue biopsy to clarify the diagnosis. 2. Flat warts: can be caused by human papillomavirus infection, flat papules. It can be treated with localized retinoic acid ointment. 3. Endocrine disorders: due to lack of sleep, irregular work and rest, excessive fatigue caused by skin cell metabolism abnormalities, appeared on the wrist spots. Pay attention to rest, keep enough sleep. 4. Excessive ultraviolet radiation: This causes the skin to release too much melanin, resulting in the formation of localized plaques. Preventive avoidance of ultraviolet radiation. If the above factors occur, it is recommended that patients go to the hospital in a timely manner, under the guidance of the doctor’s standardized treatment, the use of drugs need to follow the doctor’s instructions, avoid self-medication.