The exact cause of complex regional pain syndrome isn't well understood but may involve abnormal inflammation or nerve dysfunction.
Complex regional pain is characterized by pain that is greater than would be expected from the injury that causes it.
Treatment usually consists of medications, heat or cold therapy, physical therapy, and biofeedback.
Consult a doctor for medical advice
Sources: Mayo Clinic and others.
Fewer than 200,000 US cases per year
Treatment can help, but this condition can't be cured
Requires a medical diagnosis
Lab tests or imaging not required
Chronic: can last for years or be lifelong