7 Summits – Aconcagua 2, The Dangers of Altitude

Based on my experience at Aconcagua earlier this year, I thought I’d share with you the dangers of altitude and the importance of knowledge around it to climbers.

We all perform best at sea level, where the concentration of oxygen (O2) is 100%. Oxygen levels decrease with altitude from 100% at sea level to an altitude of Mount Everest’s summit at 8,848m of 32%. The impact of such a reduction in oxygen levels can produce a number of symptoms and possible death. High Altitude Illnesses (HAI) include Acute Mountain Sickness (AMS), High-Altitude Pulmonary Edema (HAPE), and High-Altitude Cerebral Edema (HACE).

The symptoms of AMS are typically felt by most people when they arrive at a new altitude which I felt at base camp Mount Everest (5,300m) and again at a lesser level base camp on Aconcagua at 4,300m.

The most common symptoms include headaches, gastrointestinal upset, fatigue, dizziness and sleep disruption. The more life-threatening condition of HAPE includes symptoms of shortness of breath at rest, persistent coughing, and tiredness. HACE include symptoms of difficulty walking (ataxia), feelings of confusion, or severe lethargy. Descent is the first priority when altitude illness occurs. No questions! Recover and start again ….

So, how do I, as a high-altitude climber, prepare?

I have always worked to a plan which has worked well for me – don’t fix what’s not broken!

The key parts of that plan are; get fit, get organised, get medically checked, get hydrated, get medication, get rest and get re-educated on the health impact of altitude (as above). Easier said than done but good planning well in advance is primary for me.

Hydration is #1 for me when climbing these big mountains. I remember vividly at Kilimanjaro’s Kibo high camp at 4,750m the etching on the wall, ‘’Hydrate, FFS’’! Something which has remained in my mind ever since. It is so very important. It is easy to become dehydrated at high-altitude, and hydration increases the risk of frostbite, fatigue and impairs judgment. Our bodies at altitude require at least 3 litres of water per day. Altitude increases water losses from the lungs due to the cold and dry air. There is also an increased urinary loss of water because altitude and cold have a diuretic effect. Sweating also adds to the water loss. It is recommended to drink a minimum of 1 litre of water every three hours.

Food – what to eat. Carbohydrate is the preferred energy source at altitude. Carbohydrate replaces depleted muscle glycogen (sugar stored in muscles), prevents muscle from being used as energy, and requires less oxygen for metabolism. A high-carbohydrate diet can reduce the onset and severity of AMS and improve physical performance. A low-carbohydrate diet can result in low blood sugar.

Although high-fat foods are energy dense, fat is not digested well at altitude because it requires more oxygen for metabolism than carbohydrate. When first arriving at high altitude your body uses more blood sugar as a fuel source during rest and during exercise. Muscle glycogen is not decreased but the reliance on fat for energy declines.

Put another way, fatigue and low blood sugar levels will occur more quickly at the same intensity of activity at altitude compared to sea level if increased carbohydrate intake does not occur. This is the main reason why most climbers return from a high altitude climb with significant weight loss, as I did when I returned from Mount Everest some 20kgs lighter.

But you must always remember eating whatever is on offer is better than not eating at all as the menu at high camp may not be to your liking. Altitude, believe me, does reduce your appetite so you have to make a conscious effort to eat and force feed yourself! Eating is key, no matter what it is and what it looks like. On average a climber on Mount Everest will burn 10,000 calories on summit day which compounds the need to eat, eat and eat, and of course hydrate, lots!

Coping with altitude is not easy, especially if you are feeling unwell, your physical well-being is paramount and being conscious of this can be vital. If you read my last blog you will understand. It is vital to ascend gradually. It is recommended not to climb above 300–500 meters a day, and after every 1,000 meters take a day off to rest. But as you reach high camp of any mountain you will be fully acclimatised following the rotation routines – climb high, sleep low is the general rule.

On all my high altitude climbs I have taken Diamox and it has worked for me. Diamox fools the body by registering excess CO2 and increases deeper and faster breathing, which in turn increases the amount of oxygen in the blood. It is also a diuretic and reduces any excess fluid on the vital organs. Some side effects which I’ve found very tolerable. I’d rather be well and enjoy my climbs than suffer throughout! Aspirin or Nurofen can be used.

Preparation; physically and mentally, is always key. Arriving at these high mountains with no doubts makes for such a more enjoyable expedition and summit. Till the next blog ….

Bring It On! Derek

DBA my friends …. Dream, Believe, and you will Achieve. 

Derek, is supporting the mental health charity, GROW, raising mental health awareness. If you’d like to donate please click the link: Donate to Derek Mahon 7 Summit Challenge Charitable Fund.