The disappearance of half-moon mark may be caused by slow metabolism, hypothyroidism, malnutrition and other reasons. 1. Slow metabolism: If you don’t like to exercise for a long time, it may lead to the metabolic efficiency of the body is reduced, so that the cell division at the nail bed of the nails is slower, causing the disappearance of half-moon scars. 2. Hypothyroidism: patients with hypothyroidism are prone to fatigue due to insufficient thyroid hormones, resulting in poor metabolism and the disappearance of half-moon scars. 3. Malnutrition: If there is a lack of nutrients, the body is in a state of insufficient trace elements and vitamins, which will also cause the body’s metabolism to be less efficient, resulting in a slower division of the nail beds and the disappearance of the half-moon scars. There may be other reasons for the disappearance of the half-moon mark, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.