Thumb with horizontal raised lines generally refers to a thumb nail that has horizontal lines and is raised. There are many diseases that cause this phenomenon, such as onychomycosis, nail dystrophy, lichen planus and so on. 1. Nail groove inflammation: it is an inflammation of the nail groove and its surrounding tissues formed by the skin along the sides of the finger (toe) nails, which can be caused by excessive manicure, tearing barbs and other factors. The main symptoms can be manifested as redness, swelling and pain in the tissues around the nail. 2. Nail dystrophy: it is a kind of disease that causes various abnormalities of nail plate due to the disorder of nail plate formation, which can be caused by heredity, skin disease and so on. The main symptoms can be seen in patients with thickening and turbidity of finger (toe) nails, loss of luster on the surface of the nail, roughness, longitudinal ridge and so on. 3. Lichen planus: it is a chronic inflammatory skin disease, which can be related to immunity, heredity, infection and other factors. The main symptoms can be seen in the clear border of purple-red polygonal flat papules, nail plate thinning, longitudinal ridge. If the thumbnail has horizontal lines and raised, you should immediately go to the hospital, hospital-related examination to clarify the cause of the disease, and actively cooperate with the doctor’s treatment.