The most common risk factor of<unk>  is trauma. Other risk factors include coagulopathies, infections and vascular abnormalities. It can occur spontaneously. Childhood and senility are unchangeable risk factors.
Epistaxis risk factors
Tetanus risk factors
Hyperthermia risk factors
Strongyloidiasis risk factors
Lower gastrointestinal bleeding risk factors
Hematuria risk factors
Filariasis risk factors
Bacterial vaginosis risk factors