The presence of vertical lines on the nail is a normal phenomenon if it refers to the presence of stripes on the nail itself, which can look reflective, and the presence of vertical lines on the nail itself, which is a sign that the nail is healthy. However, if there is a black vertical stripe on the nail, it should be considered a case of nail black line, which is actually directly related to the nail matrix melanocyte aggregation. If the patient has a nail that appears occasionally, the vertical line itself is very regular and the color does not change significantly, you can continue to observe. If the nail has a very unclear border, or if there is a significant change in shape or color, it should be examined by a doctor in a timely manner.