They generally develop after thermal or traumatic injury that involves the deep layers of the dermis and express high levels of TGF-β.

[citation needed] Mechanical tension on a wound has been identified as a leading cause for hypertrophic scar formation.

Hypertrophic scars usually improve over one or two years, but may cause distress due to their appearance or the intensity of the itching; they can also restrict movement if they are located close to a joint.

Silicone gel sheets may improve the appearance of scars slightly compared with applying onion extract, and may reduce pain compared with no treatment with silicone gel sheets or pressure garments.

[9] Cryosurgery, using extreme cold to remove dead tissue, may speed up the healing process from a hypertrophic scar to a flatter, paler one.