Altitude Sickness on Pakistan Treks: Symptoms, Prevention and What to Do
Altitude sickness can affect anyone who goes high quickly, regardless of age or fitness. In northern Pakistan you reach altitudes where it matters surprisingly fast: a day trip to the Khunjerab Pass climbs to 4,693 m, the Deosai plateau lies above 4,000 m, and our treks go to 5,150 m at K2 base camp and higher on pass crossings.
The good news is that most altitude illness is preventable and treatable if it is recognised early. This guide explains the warning signs, the rules of thumb that keep you safer, and how altitude is handled on our routes. It is general information, not medical advice: talk to a doctor or travel clinic before a high trip.
Why altitude affects you
As you climb, air pressure falls and each breath delivers less oxygen. The body adapts over days by breathing faster and making other changes, a process called acclimatisation. Problems arise when you ascend faster than your body can adjust. Altitude illness typically appears from around 2,500 m upwards and becomes more likely the higher and faster you go.
Fitness does not protect you. Very fit people sometimes walk too fast and climb too quickly because they feel strong. Previous good experiences at altitude are a useful guide, but they cannot predict how you will feel next time.
The three conditions to know
Acute mountain sickness (AMS)
AMS is the common, milder form. The typical picture is a headache together with one or more of nausea or loss of appetite, unusual tiredness, dizziness or poor sleep, usually starting several hours after arriving at a new altitude. Mild AMS often settles with rest at the same altitude, but it is a clear signal not to go higher until symptoms have gone.
High-altitude cerebral oedema (HACE)
HACE is a life-threatening progression of AMS. Warning signs include confusion, unusual behaviour, severe drowsiness and loss of coordination, such as being unable to walk in a straight line heel to toe. It needs immediate descent and urgent medical help.
High-altitude pulmonary oedema (HAPE)
HAPE affects the lungs and can occur with or without AMS. Signs include breathlessness at rest, a marked drop in the ability to exercise, a persistent cough and sometimes chest tightness. It is also an emergency: descend and seek medical help.
Rules of thumb that keep you safer
- Go up gradually. Widely used mountain-medicine guidance suggests that above about 3,000 m you should not raise your sleeping altitude by more than roughly 500 m a day, with a rest day every three to four days.
- Climb high, sleep low where the route allows it, for example visiting a pass and returning to a lower village for the night.
- Walk slowly enough to talk, especially on the first days above 3,000 m.
- Never go higher with symptoms of AMS. Rest until they resolve, and descend if they get worse.
- Descend at once for any sign of HACE or HAPE, even at night, with someone accompanying you.
- Drink to stay hydrated and avoid alcohol and sleeping pills at altitude; dehydration does not cause AMS but makes symptoms harder to read.
- Ask your doctor about medication before the trip. Some doctors prescribe preventive medicines for high treks; whether they suit you is a medical decision.
Where altitude matters on our routes
Altitude enters Pakistan trips in two ways: high road crossings on tours, and sustained height on treks.
On tours and road journeys
Road journeys often cross the Babusar Pass on the way north, and several tours make a day excursion to the Khunjerab Pass at 4,693 m, returning to sleep lower in Gulmit or Sost. The Deosai Plains safaris camp on a plateau listed at about 4,114 m. Short visits like these rarely cause serious illness, but headaches and breathlessness are common; move slowly at the top and tell your guide if you feel unwell.
On treks
Treks keep you high for days. The K2 Base Camp trek reaches about 5,150 m, the Snow Lake trek crosses the Hispar La at about 5,151 m, and the Mazeno Pass is listed at about 5,390 m. Our itineraries build in rest days and reserve days, which our guide to acclimatisation on Pakistan treks tabulates trek by trek. Those days are part of your safety margin, not spare time to be skipped.
Remoteness changes the calculation
On a glacier such as the Baltoro, the nearest road may be several days' walk away, and evacuation by helicopter depends on weather and on arrangements made in advance. That is why descending early, on foot, while you can still walk, is so important, and why insurance that covers helicopter evacuation is essential. Helicopter rescue fees are listed as not included in our trek programmes, and our guide to travel insurance for treks explains what cover to look for.
Carry any medicines your doctor recommends, tell your guide about any health conditions before the trek starts, and agree with your companions that anyone may say they feel unwell without embarrassment. Most serious cases develop when early symptoms are hidden.
Frequently asked questions
At what altitude does altitude sickness start?
Symptoms usually appear from about 2,500 m upwards, and the risk rises with greater height and faster ascent. Skardu and Hunza sit lower than that, but many excursions and all of our high treks go well above it.
Can I get altitude sickness on the Khunjerab Pass day trip?
A short visit to 4,693 m can bring on headache, light-headedness or breathlessness. Because tours return to sleep lower the same day, serious illness is uncommon, but take it slowly at the top.
Does being fit prevent altitude sickness?
No. Fitness helps you manage the physical effort but does not prevent altitude illness. Ascent rate and individual susceptibility matter far more.
What should I do if I have a headache at camp?
Tell your guide, rest, drink and do not go higher until it has gone. If it worsens, or if you notice confusion, clumsiness or breathlessness at rest, descend.
Is the information on this page medical advice?
No. It summarises widely used guidance so you know what to look for. Get personal advice from a doctor or travel clinic before your trip, especially if you have a medical condition.
Plan a trip that respects altitude
If you are unsure how high a trip goes or how quickly, ask us before you book. We can explain where the rest days fall and suggest a lower route if that suits you better. For fitness and kit, see our guide to preparing for high-altitude trekking, or get in touch through the contact page.