As a pioneer in India's trekking community, Indiahikes has spent over 15 years raising awareness about the medical well-being of trekkers in the mountains.

We are putting out this detailed piece of information on High-altitude pulmonary edema with the same intention. Over several years of training, observation, and experience with tens of thousands of trekkers, we have cracked down on how to avoid it to a large extent. 

If you are a hard-core trekker reading this, then you know what HAPE is and how fatal it can get. If you are a beginner or new to trekking at high altitudes, you should read it carefully.

This piece of article is not just for trekkers. If you are planning a bike ride to Leh or flying to a high altitude, this is a very beneficial read.

So, without further ado, let’s start with:

What is High Altitude Pulmonary Edema?

Pulmonary means relating to the lungs.

Edema is the swelling caused by too much fluid trapped in a particular body tissue.

When you are at a high altitude, there’s less oxygen pressure, which means the concentration of oxygen molecules in the air is lower. As a consequence, you breathe less oxygen per breath at higher altitudes. 

So, if I ask you to take a deep breath, say, at an altitude of 2,000 ft. your lungs will consume sufficient oxygen without exerting any pressure. But at 8,000 ft, you’ll need to breathe a lot harder to consume the same amount of oxygen. At the end of the day, your lungs exert a lot of pressure for very little oxygen.

In some cases, because of high pressure on the arteries, fluid from the blood leaks into air sacs in the lungs and that’s when a trekker/traveller in high altitudes is affected with HAPE.

When HAPE occurs, a trekker is essentially drowning in his body fluids. And when the lungs are incapacitated, the rest of the body soon stops functioning. This means HAPE can get fatal very soon.

Before I dive deep into HAPE, I want you to know about its initial stages — Acute Mountain Sickness, because often, when left untreated or undetected, AMS can soon turn into HAPE (although it is important to note that HAPE can occur without preceded by AMS).

What is Acute Mountain Sickness (AMS)? 

Any sickness that is caused because of gaining altitude is termed acute mountain sickness, often also called altitude sickness. It starts occurring as you climb over 8,000 ft above sea level. On average, 10% of trekkers can face some sort of altitude sickness. 

It all depends on how your body is getting acclimatised at the high altitude. The quicker it adapts, the lower the chances of getting AMS.

There’s one thumb rule for gaining high altitude: Give your body the time to adapt to the altitude and the low air pressure that comes with it. You will always observe trekkers in your group who have given more time to their body to rest will acclimatise well as compared to people who gain altitude in less time.

Travelling via flights to high altitudes is the riskiest. Yes, you read this right. Say you are travelling from Delhi to Leh; Delhi's elevation is between 650 and 820 feet and Leh is at an altitude of 11,480 feet. You are gaining this altitude in a few hours. This is very little time for your lungs to adjust to such low oxygen pressure.

What are the symptoms of acute mountain sickness?

Here are some of the most common symptoms of acute mountain symptoms 

• Headache: You feel an extreme headache. Please note: In most cases, the headache will happen but we shouldn’t just look for a headache to detect if it’s AMS. 
• Nausea/vomiting: You feel overcome by nausea or might have a feeling of vomitting.
• Fatigue: You feel extremely fatigued. You will see a significant change in your movements on the trails. 
• Insomnia: When affected by AMS, you will struggle to sleep during the night
• Loss of appetite: You will experience a loss of appetite. You will eat less even after a long day of trek. I recommend everyone to keep a check on their eating patterns in the mountains.

As soon as you see any of these symptoms in your body, I advise you to inform your trek leader (if you are coming with Indiahikes). Our trek leaders are trained to nip these symptoms in the bud.

How to treat acute mountain sickness?

After you are affected by AMS, there’s one thing that our medical trainer, Diptarka, advises everyone to do: “Go up only when symptoms go down.”

Medicinal Treatment: Right, after you feel any of the symptoms I mentioned above, put yourself on a curative course of Diamox. 

Now as we discussed acute mountain sickness, let’s climb up slowly to HAPE.

The first question that arises is

High Altitude Pulmonary Edema Symptoms | How do I detect HAPE? 

Multiple symptoms show both at the initial stage and at the advanced stage. Below, I will share some common high-altitude pulmonary edema (HAPE) signs and symptoms

• The first symptom to look for is if you have shortness of breath at rest or if you are gasping for air even while at rest. This is one of the most common symptoms that our trek leaders at Indiahikes have observed in multiple cases.
• Look for a dry cough. Please do not ignore it, at the later stage of HAPE it might get advanced and can develop into a productive wet cough.
• You might also experience extreme fatigue & drowsiness.
• Rattling chest sound. If you put a stethoscope or simply an ear on the chest of a HAPE-affected patient, you will hear a rattling sound.
• Another symptom to detect HAPE is pale or cynatic skin colour.
• At a very late stage, you might also discover pink frothy Sputum (sputum is a mixture of mucus and saliva) 

The medical trainer at Indiahikes, Diptarka, says and I quote, “I want you to note that you don't need to first have symptoms of AMS then it will turn to HAPE. HAPE can happen directly too.”

High Altitude Pulmonary Edema treatment

Our medical trainer mentions, “HAPE is the biggest killer in the mountains if you ignore symptoms.” Hence, I will help you understand the on-spot treatment of high altitude pulmonary edema.

The rule of thumb is to lose altitude as soon as possible. 

But to ease the symptoms for the trekker and buy time to descend, you must administer the right medicines: Diamox & Nifedipine.

Nifedipine helps a patient buy time. 

Here’s the dosage of medicine you should take when you learn that you are affected with HAPE, assuming you do not have canned oxygen with you.

• Take 500 mg of Diamox immediately (even if you have taken Diamox a few hours earlier). This means two tablets of Diamox.  
• Follow it up with 20 mg of Nifedipine. In India, we mostly get 10 mg tablets of Nifedipine. So take your first 10 mg, wait for 20 minutes and then take the next 10 mg.
• This will let the tablet settle in slowly. Within 30 minutes of the second 10 mg, you should be able to breathe easier.
• Nifedipine reduces the pressure in your heart, lungs and blood vessels, giving it some space to breathe. If you remember, I told you that HAPE occurs because of high pressure around the lungs, when the air sacs start accumulating fluid from your blood.
• With these two tablets in your system, climb down as much as possible. Start your descent & reach a safe height, at least around 8,000ft., so your lungs have to put in less work to breathe.
• If you cannot reach around 8,000 ft even after six hours, repeat the dose of 500 mg Diamox and 20 mg Nifedipine and continue descending.
• You’ll be tired, but it’s a matter of life and death. You need to be at a lower altitude.
• Most trekkers recover upon reaching lower altitudes. You’ll recover too.

The process of evacuation at Indiahikes

If you are on a trek with Indiahikes, there are very minute chances you will be evacuated because of HAPE. We treat it at a very initial stage right after seeing the symptoms. But, there are certain cases where things are not under our control and we have to evacuate the trekker in an emergency. 

1. Your health is monitored three times a day. We check your vitals thrice daily, ensuring we nip any health issues in the bud, even before they show up.
2. Our trek leaders are handpicked outdoor experts. Our trek leaders are hand-picked and undergo rigorous training in wilderness first aid and emergency care. Our training is so intensive that only 70 per cent make it through our training.
3. We always have a HAM kit handy (High Altitude Medical Kit). The HAM kit contains 17 essential medicines, including three life-saving drugs. They also carry bottled oxygen. Our trek leaders are always ready to handle medical emergencies.
4. We have an evacuation kit ready for emergencies. With a stretcher, two oxygen cylinders, and an emergency shelter, our teams have tested evacuation protocols in place. They can carry out smooth evacuations even in the middle of the night. We have a complete protocol for the evacuation of a trekker. We are equipped with manpower & medical resources to bring a HAPE-affected trekker down to safety.

We cannot repeat enough that safety is in prevention. The Indian Himalayas do not allow easy evacuations. Heli rescues are unheard of on most treks. It’s extremely resource-intensive to evacuate anyone from these regions and often the weather and terrain are not on your side.  

How to prevent high-altitude pulmonary edema?

The first thing I am going to suggest here is to plan your itinerary mindfully. Give yourself rest days in between so your body gets enough time to acclimatise well.

Another, we recommend you follow a preventive course of Diamox. It helps with acclimatisation. (Read more about how Diamox helps at high altitudes.)

Below I am going to tell you in detail.

• So for most treks that gain altitude too quickly, taking a preventive course of Diamox really helps, especially if your trek climbs above 13,000 – 14,000 ft.
• In fact, even for those who suddenly go up to high altitudes, like those who drive or fly to Leh, we recommend Diamox.

| Dosage: Start with a dosage of 125 mg (half a tablet) every 12 hours 2 days prior to your trek (usually when you arrive at Delhi). Increase it to 250 mg (full tablet) every 12 hours from the day you get to the base camp and continue until you complete the trek.

• Don’t stop the course in between.

| Side effects: There aren’t too many side effects of taking Diamox. You feel a numbness/tingling sensation in your hands and feet. You pee more often (which means the medicine is doing its job). Some claim that they get a bit of loosies after Diamox. Generally, a Digene takes care of this.

Keep in mind that Diamox is a sulfa-based drug. If you’re allergic to sulphides, avoid Diamox. Again I will say, consult your doctor beforehand.

While Diamox reduces the chances of AMS hitting you, it isn’t a fool-proof medicine. Even those who are on a course of Diamox can get hit by AMS.

Busting Myths About AMS

There are a lot of myths that exist about AMS. Below I am going to attach a video where the head of our Learning & Development team, Lakshmi Selvakumaran, debunks most common myths that revolve around Altitude sickness. 

How safe are you on a trek with Indiahikes?

As I mentioned we take all mandatory steps to ensure the safety of the trekkers. Multiple procedures go behind the curtains. It starts even before the trek starts

• We check trekkers’ Blood pressure on the first day to ensure it is within an acceptable standard at high altitudes.
• We record oximeter recordings thrice every day and ensure it never gets down to our cut-off numbers.
• All the trek leaders carry with them life-saving drugs to treat AMS, HAPE, and HACE. They are trained on how to treat trekkers with these medications. 
• For an emergency HAPE case, our trek leaders carry oxygen cylinders with them.
• All campsites are equipped with a bigger oxygen cylinder. We are also equipped with stretchers for severe case evacuation.
• The most important thing that matters is the observation. Our trek leaders observe trekkers throughout & assist them as per the situation demands.
• Our trek leaders, staff, and slope managers regularly undergo extensive training to manage any medical emergency cases.

In the last two years, we have seen approximately 15 HAPE cases on Indiahikes treks. Trekkers were administered with oxygen and life saving drugs promptly. They were rescued down safely to the base camp and given required medical care in the hospital.

Wrapping Words:

This detailed post helps you understand what HAPE is and what it looks like in the mountains. You can reach out to me in the comments section if you have any questions.