When Aiming High Can Get Deadly!

If you enjoy the thrill of trekking and mountain climbing, you’ll know how amazing it feels when you reach the top and you look beyond the horizon. It’s on top of this world (literally)!

Reaching to new and higher heights is exciting and it could make you feel light-headed, which may be certainly caused by the adrenaline rush or, it may be a precursor to a serious medical issue.

In this article, we shed some light on a serious medical condition which can affect anyone when at a higher altitude, that is, Altitude Sickness.

What Causes Altitude Sickness?

Altitude Sickness (also called mountain sickness) is an illness due to the decreasing amount of oxygen above sea level altitudes that may range from a mild headache to a life-threatening build-up of fluid in the lungs or brain, and even death at moderate to high altitudes.

What Are Symptoms Of Altitude Sickness?

Altitude Sickness has a spectrum of symptoms and is a general term that covers three major syndromes. They are:

1. Acute Mountain Sickness (AMS)
People with acute mountain sickness often attribute their symptoms to other causes such as an uncomfortable bed, bad food, or a hangover.

However, it is important to recognise that these symptoms may indicate a high-altitude illness. Early symptoms of acute mountain sickness include headache, fatigue, insomnia, dizziness, nausea, decreased appetite and late symptoms include swelling of extremities and social withdrawal.

2. High-Altitude Pulmonary Edema (HAPE)
The onset of High-Altitude Pulmonary Edema can be gradual or sudden. High-Altitude Pulmonary Edema typically occurs after more than one day spent at high altitude. High-Altitude Pulmonary Edema requires immediate treatment. Symptoms can include shortness of breath at rest (early symptom), gurgling respirations, fever, wet cough with frothy sputum, several symptoms of Acute Mountain Sickness (AMS).

3. High-Altitude Cerebral Edema (HACE)
High-Altitude Cerebral Edema produces symptoms that can become progressively worse over a short time period. They include confusion (early and very important symptom), cannot do usual functions (such as hiking and skiing) because of fatigue or shortness of breath, walking and coordination becomes impaired. If left untreated, High-Altitude Cerebral Edema will ultimately result in death.

Can Altitude Sickness Be Prevented?

Yes, Altitude Sickness is preventable. The body needs time to adjust to higher altitudes. Physical conditioning has no bearing on this. Hence, everyone including children and infants, may be at some risk when ascending to higher altitudes.

For people who do not know the rate at which their bodies adjust to high altitude, the following preventive measures are recommended:

• If traveling by air to a ski area above 8,250 feet (2,500 metres), incorporate a layover of one to two days at an intermediate altitude.
• Avoid physical exertion for the first 24 hours.
• Drink plenty of fluids, and avoid alcoholic beverages.
• Consume a high-carbohydrate diet.
• If mountain climbing or hiking, ascend gradually once past 8,000 feet (2,400 metres) above sea level.
• Increase the sleeping altitude by no more than 1,000 feet (300 metres) per 24 hours. The mountaineer’s rule is “climb high, sleep low.”

Note that doctors may prescribe Acetazolamide to prevent acute altitude sickness. Acetazolamide medication speeds acclimatization. If rapid ascent is unavoidable, as in rescue missions, or if a person is prone to developing High-Altitude Pulmonary Edema, doctors may also prescribe Nifedipine.

What Altitude Does Altitude Sickness Occurs And Why?

Symptoms generally do not manifest below 1500 metres. From about 1500 to 2500 metres, symptoms are generally mild, if experienced at all. At 2500 metres, symptoms of mild to moderate Acute Mountain Sickness (AMS) become quite common among unacclimatised visitors after rapid ascent. At this altitude, High-Altitude Pulmonary Edema (HAPE) may also occur, but it is more common above 3000 metres. Above 3000 to 4000 metres, Acute Mountain Sickness (AMS) is common among people who have not properly acclimatised, and the risk of severe HAI (High Altitude Illness), including life-threatening High-Altitude Pulmonary Edema (HAPE) and High-Altitude Cerebral Edema (HACE), is substantial.

Altitude Sickness develops when the rate of ascent into higher altitudes outpaces the body’s ability to adjust to those altitudes due to the decreasing levels of oxygen in the air as altitude increases. This results in abnormally low blood levels of oxygen.

What To Do When Experiencing Symptoms Of Altitude Sickness

If symptoms such as headache or shortness of breath do not improve promptly with simple changes, visiting a doctor may be helpful if descending to a lower altitude is inconvenient and a doctor is available.

Descend immediately if you experience shortness of breath at rest, mental confusion or lethargy, or loss of muscle coordination develop. Symptoms of most people with acute Altitude Sickness improve by the time they reach a medical facility, which is usually located at a lower altitude.

When To Seek For Emergency Medical Help

Acute Mountain Sickness (AMS) symptoms should improve as you adjust to the altitude, usually within 24 to 48 hours. If your symptoms worsen at any point, you should descend and seek help.

How Dangerous Is Altitude Sickness?

It can be life threatening if not recognized and treated on time.

How Common Is This Condition?

The incidence of High-Altitude Cerebral Edema (HACE) is reported to be 0.1 to 2 percent at elevations in excess of 3000 to 4000 metres (9800 to 13,000 ft), although High-Altitude Cerebral Edema (HACE) has been reported at altitudes as low as 2100 metres. High-Altitude Cerebral Edema (HACE) is often complicated by concomitant High-Altitude Pulmonary Edema (HAPE). In fact, pure cerebral edema without pulmonary edema appears to be uncommon.

High-Altitude Cerebral Edema (HACE) appears to occur in all ages and both genders in a fashion similar to Acute Mountain Sickness (AMS). Younger males may be at greater risk for behavioral reasons, such as continuing to climb in the presence of AMS symptoms.

As with Acute Mountain Sickness (AMS), there are no physiologic, anatomic, or genetic characteristics that reliably predict susceptibility to HACE. Individuals with a history of Acute Mountain Sickness (AMS) or High-Altitude Pulmonary Edema (HAPE) are at greater risk of recurrence and of developing High-Altitude Cerebral Edema (HACE).

Useful Tips For Travelling To Higher Altitudes

• Gradual ascent — Gradual ascent is the surest and safest method of preventing or ameliorating High Altitude Illness (HAI). As a general guideline, individuals who normally reside below 1500 metres (5000 feet) elevation should avoid an abrupt ascent to sleeping altitudes above 2800 metres (9200 feet).
• Preacclimatization — Pre-acclimatization involving pre-exposure to higher altitudes (hypobaric hypoxia) or environments that simulate high altitude (normobaric hypoxia) is an effective strategy for preventing High Altitude Illness (HAI). Residing at a site above 2500 metres (8200 feet) or participating in brief climbs to actual elevations over 2500 to 3000 metres (8200 to 9840 feet) in the weeks leading up to a trip to higher elevations (approximately 4500 metres [14,800 feet], or higher) provides a degree of pre-acclimatization, and may allow for a faster rate of ascent without Acute Mountain Sickness (AMS).
• Education — Individuals with a history of HAI or significant cardiopulmonary disease should be counseled regarding their increased risk and be provided with a conservative ascent plan (or profile).
• Alcohol and drug use — Sedative-hypnotics and moderate to heavy alcohol intake should be avoided during the acclimatization process, particularly during the first two nights at a new elevation.
• Diet and hydration — Various diets, including high carbohydrate, have been touted to reduce the incidence of High Altitude Illness (HAI), but data are inconclusive
• Exertion — Vigorous exertion at altitude contributes to the development of Acute Mountain Sickness (AMS) as well as High-Altitude Pulmonary Edema (HAPE), although sedentary persons also develop these illnesses.
• Pharmacologic prophylaxis – Clinicians should reserve prophylactic medications for individuals with a history of altitude intolerance and those who must make a planned rapid ascent to high altitude.