Treat the underlying cause with a doctor
Stop smoking
Stay well hydrated
Reduce altitude exposure if possible
Treat sleep apnea
Manage lung or heart disease
Review testosterone or anabolic steroid use with a doctor
Avoid iron supplements unless prescribed
Consider regular blood donation if approved by a doctor
Undergo therapeutic phlebotomy if prescribed
Follow prescribed medications for polycythemia vera or other blood disorders
Monitor haematocrit with repeat blood tests