A vertical line in the abdomen of a woman is physiological, everyone from birth, is the two sides of the sheath of the rectus abdominis muscle and the abdominal midline intersect with each other and form, become the normal physiological tissue of the human body, called the abdominal midline or belly button line, only due to individual differences, some relatively obvious. First of all, women in the 2-4 months of pregnancy due to the influence of progesterone, this line will cross to the navel, the color shade and the pregnant woman’s own hormone level has a certain relationship, will slowly disappear within a year after delivery. Secondly, this situation has a certain influence with their own physique and endocrine, irregular lifestyle or endocrine disorders caused by a pigmentation phenomenon, but also may be too much weight gain, the expansion of the abdominal skin caused by expansion lines. To sum up, if black vertical lines appear in the abdomen, you can go to the hospital dermatology department to do an examination to exclude skin diseases.