Skin tags are small, soft growths that hang from the skin’s surface, usually flesh-colored or slightly darker. Although they may look concerning at first glance, these growths are extremely common and typically harmless. Many people first notice them in adulthood, often surprised by how suddenly they appear.

Dermatologists explain that skin tags rarely develop due to a single factor. Instead, they usually form from a combination of physical irritation, hormonal changes, genetics, and other everyday influences. Understanding why they appear can help explain their sudden arrival and when they might become more noticeable.

Friction is one of the most common causes. When skin repeatedly rubs against skin or clothing, irritation can trigger small growths over time. This explains why skin tags frequently appear in areas where skin folds are common—the neck, underarms, groin, and under the breasts. Continuous rubbing stimulates skin cells to grow outward.

Age is another important factor. Although skin tags can appear at any stage of life, many people notice them more often during their 40s or 50s. As skin ages, its internal structure changes, making it more prone to forming small benign growths. Hormonal shifts—such as those during pregnancy—can also increase the likelihood of developing them.

Body weight plays a role as well. People carrying extra weight may develop skin tags more frequently because additional weight creates more skin folds, increasing friction. Research also suggests a connection between skin tags and insulin resistance, which can sometimes signal underlying metabolic changes.

Genetics can significantly influence whether someone develops skin tags. If parents or close relatives have them, other family members are more likely to develop them too. Some individuals simply inherit a tendency to develop these harmless growths, even without obvious causes like friction or hormonal shifts.

Most skin tags are benign and don’t require treatment. However, consult a dermatologist if a growth changes color, grows rapidly, becomes painful, or begins to bleed. In most situations, skin tags are simply a normal part of how skin evolves over time, linked to everyday factors rather than anything mysterious or concerning.