What happens if broken bones are left untreated?

Depends on the bone: Some untreated broken bones (fractures) will heal without any difficulty. However, many broken bones require treatment. Some require nonsurgical treatment, but others require surgery for proper alignment and healing. Depending on the location and nature of the broken bone, some treatment is often warranted. All broken bones should ideally be evaluated by an orthopaedic surgeon.

Varies: Some fractures can heal just fine without any care. Others may not heal (non Union) or heal in a bad position leading to a poor outcome (malunion), depends on the specific fracture.