Spider nevus has the possibility of getting bigger gradually. Spider nevus is a kind of capillary dilatation, which is formed by expanding the ends of small arterial branches in the skin. Taking the nevus as the center point, small blood vessel branches will be formed radially around it, and its appearance looks like a spider, so it is called spider nevus. Some studies have shown that the main causes of spider nevi are increased estrogen levels or liver abnormalities. If the estrogen level in the patient’s body continues to increase, or if the patient’s liver function deteriorates, the spider nevus may gradually become larger. However, spider nevi are not always caused by diseases. In some healthy people, spider nevi may also occur, especially in pregnant women. Some healthy pregnant women may also develop spider nevi because the estrogen in their blood may be dozens of times higher than that of normal people. If the spider nevus appears in pregnant women, it usually does not need special treatment. If the spider nevus is caused by liver disease, it needs to actively treat the original disease to avoid affecting the patient’s aesthetic appearance.