A study in Respiratory Research defines a high altitude as any elevation greater than 1,500 meters (m) — about 5,000 feet (ft) — above sea level.
People may experience altitude-related health effects while traveling in mountainous areas or during flights.
Read on to learn more about the challenges people with chronic obstructive pulmonary disease (COPD) can face at high altitudes. We also describe symptoms of altitude sickness, and how to prepare for a trip.
Preparing for high altitude
People with COPD should change altitudes slowly.
Taking the time to plan can help people with COPD limit the effects of traveling to high altitudes.
Aim to change altitude as slowly as possible. A gradual adjustment is especially important for people with COPD.
One study of acute mountain sickness (AMS) suggests that the optimal rate of ascent should be no more than 500 m per day (about 1,640 ft) when starting at elevations higher than 2,500 m (around 8,200 ft) above sea level.
2. Talk to a doctor or pulmonologist
High altitudes can cause a range of health issues, including high-altitude pulmonary edema (HAPE). This potentially life-threatening condition involves fluid in the lungs, and it can occur in otherwise healthy individuals.
People with COPD are more vulnerable to altitude-related illnesses, including HAPE.
Other factors that increase susceptibility include:
- a history of altitude sickness
- quick increases in altitude
- final altitude
- how cold the area is
- how much exercise a person does at a high altitude
- the use of alcohol or sleeping pills
A doctor can advise about the best ways to reduce risk. They can also perform tests to assess fitness for flying or traveling to high altitudes.
3. Test COPD symptoms
To determine whether it is advisable for a person with COPD to fly or travel, a doctor may perform the following tests:
- Spirometry. This involves breathing into an instrument called a spirometer, which measures lung function.
- Diffusing capacity test. A person exhales, and the doctor sends the collected air for analysis.
- Arterial blood gas test. This measures oxygen and carbon dioxide levels in the blood.
- Oxygen saturation test. Results indicate how many red blood cells are carrying oxygen.
- The 6-minute walking distance test. Doctors use this to determine a person's capacity for functional exercise.
- Hypoxemia prediction equations. These check for a low concentration of oxygen in the blood.
- Hypoxia inhalation test. This helps determine whether enough oxygen is reaching the tissues.
After performing these tests, a doctor may recommend traveling with supplemental oxygen.
4. Take it easy at high altitudes
Limiting exercise, alcohol consumption, and the use of sleeping pills during the first 2 days at a high altitude may minimize the occurrence and severity of symptoms.
Results of a study published in Sports Health indicate that athletes may be especially vulnerable to acute high-altitude illness. The authors emphasize that changing altitude slowly helps to reduce strain on the body.
High altitude and COPD risks
People with COPD have a high risk of symptoms worsening at high altitudes, even if symptoms are stable at low altitudes.
Preexisting diseases like COPD can magnify the effects of decreased oxygen, worsening symptoms of altitude sickness and related conditions.
People with moderate to severe COPD often develop symptoms due to a lack of oxygen, according to a 2012 case report concerning air travel and COPD.
The authors refer to another study, which found that 25 percent of people with COPD experience symptoms of a lack of oxygen while flying.
Authors of a 2011 study concluded that people with severe or exacerbated COPD should not travel to elevations above 2,000 m (about 6,500 ft), but that people with stable COPD may be able to comfortably travel to elevations of 2,000–3,000 m (around 6,500–10,000 ft).
Altitude sickness can include headaches, fatigue, and weakness.
The Lake Louise Scoring System helps to diagnose AMS, the most common altitude sickness. It scores the five most common symptoms from zero to three:
- gastrointestinal symptoms
- fatigue and weakness
- dizziness or lightheadedness
- difficulty sleeping
A score of zero means that a person has no symptoms, and three represents severe symptoms. For example, a score of three for gastrointestinal symptoms indicates severe nausea and vomiting.
If a person's total score is between three and five, they may have mild AMS. A total score of ten or higher can indicate severe AMS.
Anyone with AMS symptoms should not travel to higher altitudes.
When to see a doctor while traveling
People who have traveled to higher altitudes in the past few days should seek medical attention if they have a headache and any of the following symptoms:
- difficulty sleeping
Living at a high altitude with COPD
People with COPD have a higher risk of mortality if they live at a high altitude. The author of a 2014 review reported, "There is a broad consensus that mortality from COPD increases with altitude."
Risks of living with COPD at a high altitude could include:
- hypoxia, or a lack of oxygen reaching the tissues
- high blood pressure
- heart enlargement
- overproduction of red blood cells
The author advised that if a person's COPD is progressing, they would benefit from moving to an oxygen-rich area closer to sea level.
Always consult a doctor when traveling to an elevation higher than 2,000 m (about 6,500 ft) above sea level.
Medical professionals can recommend ways to make travel more comfortable. For some people, they may suggest taking supplemental oxygen, or they may discourage travel.
Anyone who experiences headaches, fatigue, nausea, dizziness, or difficulty sleeping at a high altitude should seek medical attention.