Soroche: How to Prevent and Treat Altitude Sickness

Soroche or altitude sickness is the most common complication of the Andean Peru trip. Affects 30-50% of travellers going direct from sea level to over 2,500 metres. The good news: with preparation and adequate management, symptoms are mild and manageable. The bad news: ignoring it can become serious complication. This guide describes concrete medical data.

Which Peruvian destinations require altitude attention

Peru has three altitude levels:

No risk (less than 1,500 metres): Lima (150 m), Trujillo, Chiclayo, Iquitos, Tarapoto, Tumbes, Piura.

Low risk (1,500-2,500 metres): Arequipa (2,300 m), Aguas Calientes (2,040 m), Machu Picchu (2,430 m), low Colca Canyon zone.

Medium-high risk (2,500-3,500 metres): Sacred Valley (2,800 m), Ollantaytambo (2,700 m), Pisac (3,000 m), Cusco city (3,400 m), Sacsayhuamán (3,700 m).

High risk (3,500-4,500 metres): Lake Titicaca (3,812 m), Puno (3,819 m), Cruz del Cóndor (3,300-4,000 m), Salkantay pass (4,630 m), Lares pass (4,300 m).

Above 5,000 metres (Salkantay summit at 6,270 m, Ausangate at 6,384 m): only travellers with high-mountain experience.

Soroche symptoms

Symptoms appear 6-24 hours after going up to altitude. Classified in three levels:

Level 1 — mild (affects 30-50% of travellers). Headache, mild fatigue, dizziness on position change, slight breathlessness climbing stairs, interrupted sleep. Tolerable symptoms, manageable with rest and hydration. Most disappear after 24-48 hours at altitude.

Level 2 — moderate (affects 10-15% of travellers). More intense headache not responding to paracetamol, lack of appetite, nausea, marked fatigue, sleep difficulty. Requires attention: forced rest, light oxygen therapy (concentrator), specific medications.

Level 3 — severe (affects 1-3% of travellers). Incapacitating headache, persistent vomiting, coordination loss, mental confusion, breathing difficulty at rest. Medical emergency. Requires immediate descent and hospital care.

Alarm symptoms that are NOT normal: persistent vomiting (more than 4-6 hours), mental confusion, balance loss, cough with pink phlegm, breathing difficulty at rest. These require immediate descent.

Prevention: five steps

Step 1: gradual acclimatisation. Enter Sacred Valley (2,800 m) before Cusco (3,400 m). Spend first night at lower altitude. Go up to Cusco gradually.

Step 2: constant hydration. Drink 3-4 litres of water daily on arriving at altitude. Altitude dehydrates faster than sea level. Avoid alcohol first 2 days.

Step 3: reduced activity first two days. Walk slowly. No running, no fast stair climbing. Body needs 24-48 hours to produce more red blood cells.

Step 4: light eating. Small frequent meals with carbohydrates (pastas, potatoes, bread). Avoid fatty meals, heavy meats, copious meals.

Step 5: coca leaves and mate. Coca mate (tea with leaves) helps oxygenation. Available at all hotels. Coca leaves to chew are alternative. They are NOT drugs; they are millennial traditional use approved by WHO for travellers.

Medications: options

Three medication options, in order of efficacy:

Acetazolamide (Diamox): first-line medication. Begin 24-48 hours before going up, continue first 3-5 days. Dose: 125 mg twice daily (preventive) or 250 mg twice daily (treatment). Prescription required. Cost: USD 15-30 per treatment.

Sorojchi pills: over-the-counter Peruvian medication, combines acetazolamide with caffeine and aspirin. Available at Peruvian pharmacies (Inkafarma, Mifarma). Take on noticing symptoms. Cost: USD 8-12 per box of 12 pills.

Ibuprofen or paracetamol: for level 1 headache. NOT soroche treatment itself; only relieves the symptom.

Some premium hotels (Belmond, Inkaterra) offer in-room concentrator oxygen therapy. 30 minutes of supplementary oxygen quickly relieve mild to moderate symptoms. No additional cost at top hotels.

When to descend: criteria

Descending altitude (descend 500-1,000 metres, ideally to Sacred Valley or Aguas Calientes) is indicated in these situations:

Level 2 symptoms not improving after 24 hours with treatment.

Any level 3 symptoms (persistent vomiting, confusion, breathing difficulty).

Child or older adult with rapidly worsening symptoms.

Person with pre-existing condition (cardiac, respiratory) presenting symptoms.

Descent is generally curative: most symptoms disappear in 6-12 hours by descending 1,000 metres.

Special cases

Pregnant women: altitude during pregnancy is not clearly contraindicated, but we recommend avoiding more than 3,000 metres in first trimester and consulting obstetrician before the trip.

Children under 5: more vulnerable to soroche. Symptoms may be irritability and insomnia, not explicit headache. Consider avoiding Cusco direct (prefer Sacred Valley or avoid trip until 5 years).

Older adults with conditions: cardiac, severe hypertension, COPD, poorly controlled diabetes. Mandatory medical consultation before trip. Altitude can aggravate these conditions.

Athletes: without specific altitude training, are not immune to soroche. Sea-level aerobic condition does not protect against altitude hypoxia.

Soroche is not "overcome" with willpower. It is physiological response to hypoxia. Acclimatisation is the only scientifically proven prevention method. Going direct to Cusco from Lima is ignoring physiology, not demonstrating resistance.

Kada Travel

Common myths

Three myths to dismantle:

"Being in good physical shape protects from soroche". False. Sea-level aerobic condition does not translate to better altitude adaptation. Professional soldiers and Olympic athletes can have soroche just like sedentaries.

"Alcohol helps with altitude". False. Alcohol dehydrates, suppresses nocturnal breathing, and aggravates symptoms. Avoid alcohol first 2 days at altitude.

"Chinese or natural pills are as good as acetazolamide". False. Only acetazolamide has scientific effectiveness evidence. "Anti-soroche" supplements at online pharmacies are not reliable.