“Finger lines are a sign of serious illness” is not true, finger lines may be physiological factors, nail malnutrition, nail mother mole and other reasons. 1. Physiological factors: If affected by congenital or genetic factors, some people will be born with vertical lines on the fingers, which is a normal physiological phenomenon. 2. Nail malnutrition: If the nail is malnourished, the lack of calcium ions in the body may cause the nail to become rougher and appear vertical lines. If the body lacks vitamin A, it may lead to the symptoms of vertical lines on the nails. 3. Mole of the nail: Mole of the nail is a kind of mole that grows at the root of the nail, and the melanin brought out by the mole cells may form longitudinal black lines, which leads to vertical lines on the fingers. Vertical finger lines may also be caused by other reasons. You can go to the local hospital for examination to clarify the cause of the vertical lines and take targeted treatment.