See a healthcare professional to find and treat the cause
Stop smoking
Stay well hydrated
Treat sleep apnea if present
Manage chronic lung or heart disease
Avoid high altitude exposure when possible
Review medications and supplements with a clinician
Stop testosterone or anabolic steroids only under medical supervision
Treat dehydration, vomiting, or diarrhea promptly
Donate blood only if approved by a clinician
Follow prescribed treatment for polycythemia vera if diagnosed
Monitor blood counts as directed by a clinician