Nail crescent slowly becoming less may be caused by malnutrition, aging, hypothyroidism and other reasons. 1. Malnutrition: It refers to the growth, development and dysfunction of the body caused by long-term insufficient intake, malabsorption or increased consumption of protein, energy and other nutrients in the diet. Patients mainly manifested as significant weight loss, fat reduction or disappearance, growth retardation, wasting, metabolic reduction and other phenomena. Due to the decrease in metabolism, the phenomenon of slowly diminishing fingernail crescents can occur. 2. Aging: It refers to the phenomenon that the physiological and psychological adaptability of the body to the environment decreases progressively and gradually tends to die. The metabolism slows down with age, and the nail crescent slowly becomes less and less. 3. Hypothyroidism: It may be due to drugs, surgery, thyroiditis and other reasons that lead to a decrease in the secretion of thyroid hormones, resulting in hypothyroidism, showing symptoms of low metabolism, which can make the nail crescent slowly diminishing phenomenon. It is recommended that patients with slowly diminishing fingernail crescents go to the hospital in time, do relevant examinations, and follow the doctor’s instructions for treatment after clarifying the cause of the disease.