Nails in the middle of the touch a little convex is often due to the following reasons: First, the diet is too single, the lack of nutrients caused by the elements, when the patient has been drinking or eating spicy food, and does not intake of food rich in vitamins and fiber, will cause uneven nails, which can be appropriate to eat more green vegetables, appropriate to more intake of low-fat and low cholesterol content of high-quality proteins, such as fish, shrimp, etc., appropriate to more Intake of foods rich in unsaturated fatty acids, such as walnuts, peanuts, sesame, etc., to help flatten the finger; second, the local has been squeezed or trauma caused when the injury will lead to the nail bed is damaged, it will cause unevenness of the nails, which is generally do not have to worry about it too much, with the restoration of the nail bed, the nails can be gradually flattened. If the unevenness is obvious, you can go to the hospital to find a doctor to check.