Dehydration at High Altitudes - Symptoms, Causes, Treatments

Dehydration is serious business on a trek. It is one of the biggest ailments that holds back trekkers from completing treks. The symptoms of dehydration are so similar to those of Acute Mountain Sickness (AMS). So, often, trekkers confuse the two. Our founder, Arjun Majumdar explains how to recognise dehydration and what to do about it.

Simply put, dehydration occurs when the amount of liquid a person loses is more than the amount he gains. When on treks, it is easy to get hot and sweat a lot. At high altitudes, because of decreased pressure, you breathe deeper and faster. More water vapour is lost through breathing. The body’s natural response to this is to activate mechanisms to regain normal temperature. Losing heat in this case involves sweating, which again loses vital water stores.

The symptoms of dehydration are (in increasing order of the appearance of the symptom): 

• Thirst
• Dry mouth, lips and nose
• Headaches
• Fatigue and lethargy
• Deep, rapid breathing
• Rapid, weak pulse of 100 bpm at rest
• Dizziness and feeling light-headed
• Temperature drop, especially the extremities
• Sunken, dry eyes
• Blue lips
• Low blood pressure
• Muscles cramping
• Painful kidneys

At a moderate stage, dehydration can cause abnormalities in sodium and potassium levels in the body. To counter the effects on the body, it is important to drink plenty of water to replace the lost fluids. Dehydration is a serious condition and can need hospitalisation.

Another reason it is important to stay hydrated is that the symptoms are similar to Acute Mountain Sickness (AMS). Confusion with dehydration can be avoided by staying hydrated, allowing for easy recognition of AMS.

If you aren’t drinking enough and think you might be dehydrated, conduct these two simple tests on yourself immediately:

1. Examine your urine. Clear or straw coloured urine denotes sufficient liquid intake. A dark orange or yellow tint means waste is concentrated and so you should drink more, even if you don’t feel thirsty.

2. Lightly pinch a soft area of skin such as the back of your hand and it doesn’t return to its normal position quickly then it is likely that you are dehydrated.

Dehydration is a killer on the hills and very few realize it. At your base camp, you will start to dehydrate just by doing nothing. You need to drink 5-6 litres of water every day on the trek. If you are not used to this, it can be difficult. As a tip, start practising to drink 5-6 litres of water everyday, 15 days before your trek. Never drink more than 500 – 600 ml at a time.

Remedial action: If on the trek, you feel uneasy or short of breath or just tired, perhaps with a mild headache, suspect dehydration. Drink one  litre of water and take a Disprin. If your uneasiness or headache has not disappeared totally in an hour, then you could have been struck by AMS. Talk to your Trek Leader immediately.

Note on AMS: Please read this article on AMS and why the use of Diamox accelerates acclimatization: 

To accelerate acclimatisation, we advise trekkers to be on a course of Diamox while on the trek. Start the course a day before you reach the camp.

Please note: While Diamox is a harmless enough drug, it is not recommended for those who are allergic to sulpha drugs or have high/low BP issues. Please check with your doctor before starting on a course.