Altitude Sickness
This is the main health issue for visitors to the Andes. Cusco sits at 3,400m, Puno at 3,850m, and the Colca Canyon trailheads are higher still. Symptoms of acute mountain sickness (AMS) include headache, nausea, fatigue, and dizziness, typically within 12 to 24 hours of arriving at altitude.
The best remedy is time. Give yourself a day or two in Cusco before exerting yourself. Avoid alcohol and heavy meals on arrival. Coca leaf tea (mate de coca) is widely drunk and helps many people; coca leaves are legal throughout Peru and sold everywhere. Acetazolamide (Diamox) can be prescribed by a doctor before your trip as a preventive measure; consult your GP or a travel clinic.
Descend immediately if symptoms are severe or include confusion, ataxia, or breathing difficulty. These are signs of high-altitude cerebral or pulmonary edema, which are life-threatening.
Water and Food
Do not drink tap water anywhere in Peru. Bottled water is cheap and universally available. Ice in restaurants is often made from tap water. Be cautious with raw vegetables washed in tap water and with street food in areas with poor sanitation.
Traveler's diarrhea is common. Bring oral rehydration salts and know the signs of more serious infection.
Vaccinations
No vaccinations are required to enter Peru, but the CDC and most travel clinics recommend being up-to-date on routine vaccines and having hepatitis A and typhoid vaccinations. Yellow fever vaccination is required if you are arriving from certain other countries; it is also recommended if you plan to travel into the Amazon jungle. Consult a travel clinic at least four to six weeks before departure.
Mosquitoes
Malaria exists in the Amazon lowlands. Dengue fever is present in tropical regions and has no vaccine (as of 2025). Use DEET-based repellent, wear long sleeves at dusk, and sleep under a mosquito net if your accommodation doesn't have screens.
Medical Facilities
Good private clinics are available in Lima. In Cusco and Arequipa, clinics catering to tourists are accessible. Beyond the major cities, medical care is limited. Travel insurance with evacuation coverage is strongly recommended.