Photo: How altitude affects you
Air pressure falls with height, so each breath brings in less oxygen. The body responds by breathing faster and producing more red blood cells over days. This takes time, and the speed of the climb matters more than the final height. A slow ascent through Gilgit, Hunza and Skardu gives the body room to adapt.
Fitness does not protect against altitude illness. Fit travellers can be affected as readily as others, and young men are sometimes at higher risk because they push on. The main defence is a gradual climb, rest days and honest attention to how you feel. Alcohol and dehydration make symptoms worse.
Sleep and breathing
Breathing patterns change at night, and brief pauses in breathing are common above 3,000 metres. Sleep is often light and broken for the first nights. This is usually harmless, but a headache that builds overnight can be an early sign of altitude sickness.
Symptoms and what they mean
Acute mountain sickness is the common form. It usually appears within a day of climbing and brings headache, nausea, dizziness, poor sleep and breathlessness on effort. Mild cases often settle with rest at the same altitude and no further climbing.
More serious forms are rare but need fast action. High altitude cerebral oedema causes confusion, unsteadiness and severe headache. High altitude pulmonary oedema causes breathlessness at rest, a persistent cough and extreme tiredness. Both are medical emergencies, and descent is the priority.
Symptoms can appear at modest heights in some people. Treat any new headache at altitude as a warning and check how it develops over a few hours. Do not climb higher while symptoms are getting worse.
When to descend
Descend if symptoms worsen despite rest, or if there is confusion, breathlessness at rest or an unsteady walk. A drop of several hundred metres often brings relief. Do not leave a seriously unwell person alone, and arrange transport or help early where roads allow.
Heights on northern routes
The Karakoram Highway climbs steadily from the lowlands through Chilas and Gilgit towards Hunza. Khunjerab Pass, on the border with China, is very high, and most travellers cross it as a day trip from Karimabad or Gulmit. The gain is large, so keep the stop short and return to a lower valley to sleep.
The road east to Skardu follows the Indus and then the Shyok. Skardu itself is high enough to notice, and the Deosai plateau is higher still. Babusar Pass, on the route between Kaghan and Chilas, is also high and is usually open only in the warmer months. Check road conditions before setting out.
Some valleys and lakes sit above 4,000 metres. Visits are possible with a slow approach, but a night at that height should follow several days of gradual gain. Where a high point can be seen as a day trip from a lower base, that is usually the safer choice.
Permits and advice
Some border districts and areas near the Line of Control require a No Objection Certificate. Rules change, so check current official advice before travel. This page covers health only and does not replace medical advice.
Preparing for high travel
Build the journey around a slow start. A night in Gilgit or Chilas, then a night in Hunza, then onward travel, suits most people. Keep the first days light and save the hardest walking or the highest pass for later in the trip. A rest day costs little and prevents most problems.
Carry water, food, warm layers and sun protection. Weather changes quickly on high roads, and a warm jacket matters even in summer. Mobile coverage is patchy, so share your route and expected return with someone. Travel insurance that covers trekking and evacuation is worth arranging before leaving home.
If you take regular medicine, bring enough for the whole trip in original packaging. A basic first aid kit, a written medical summary and a means of calling for help are sensible. Groups should agree in advance that anyone can call a halt without argument.
Children and older travellers
Children generally adjust at similar rates to adults but may not describe symptoms clearly. Watch for irritability, poor appetite and unusual sleepiness. Older travellers with heart or lung conditions should seek medical advice before going high, and keep gains slow.
Frequently asked questions
At what height does altitude sickness start in northern Pakistan?
Symptoms can appear above roughly 2,500 metres, and the risk rises with height and speed of ascent. Gilgit at about 1,500 metres is usually fine. Hunza, Skardu and the high passes sit well above that, so a gradual climb and rest days reduce the chance of illness.
Is altitude sickness a risk on the Khunjerab Pass day trip?
Yes. The pass is very high, and a day trip from Hunza gains height quickly. Most people manage a short stop, but headache and breathlessness are common. Keep the visit brief, avoid exertion and return to a lower valley to sleep rather than staying high.
What should you do if someone becomes unwell at altitude?
Stop climbing and rest. If symptoms worsen, or there is confusion, breathlessness at rest or an unsteady walk, descend to a lower altitude and seek medical help. Do not leave the person alone, and arrange transport early where roads allow.
Do you need a permit for high routes in Gilgit-Baltistan?
Some border districts and areas near the Line of Control require a No Objection Certificate, and rules change. Check current official advice before travel. Permits are separate from health planning, so confirm both before setting out on remote high routes.
