Finger nails with horizontal lines are mainly manifested as gastrointestinal disorders, gastrointestinal diseases. Fingernails with horizontal lines is a digestive system problems, if the horizontal lines are divided into fine, coarse horizontal lines, according to the different horizontal lines performance is not the same, such as horizontal lines and fine, may be seen in chronic long-term digestive system diseases, dietary inattention will appear abdominal pain, diarrhea, chronic colitis and other symptoms. Deep and thick horizontal lines, indicating more serious gastrointestinal diseases, and at the same time the location of the horizontal lines with the growth rate of the nail has a half-yearly change in the characteristics, so if half of the nail has horizontal lines, indicating that 3 months ago or so there has been a gastroenteritis.