Hypertrophic scar is characterized by protruding surface, irregular shape, unevenness, flushing and congestion, firmness and tenacity, burning and itching. Hypertrophic scar is characterized by rising ambient temperature, emotional excitement, or aggravated symptoms when eating spicy and irritating food. Hypertrophic scars usually last for months or years before they gradually degenerate.

Hypertrophic scar, early local swelling, hardening, congestion, the surface of its tissue structure is covered by a layer of atrophic epithelial cells, the middle layer has vasodilation and inflammatory cell infiltration, the bottom layer has less collagen fibers, and the connective tissue proliferates a lot. This kind of scar is higher than the skin surface, and it thickens and hardens locally in the early stage. The capillaries are red or dark red with congestion.

Generally, the base of scar is not attached to deep tissue, which is pushable and contractile. Most of them will not cause serious dysfunction, but will affect the face and exposed parts, so they often need treatment.