A man is shown skiing in the mountains. Many people in Colorado experience various stages of altitude sickness every day.

Last time you went skiing in Vail, you had a headache all day and didn't sleep well that night. When your relatives from Florida came to visit last summer and got sick up in Aspen, it probably wasn't a bug. You — and they — may have had altitude sickness.

Living on the Front Range, even at 5,000 or 6,000 feet, doesn't make you immune to it, according to Dr. Todd Bull, medical director of the UCHealth Comprehensive Lung and Breathing Program located on the Anschutz Medical Campus in Metro Denver. Bull is also the director of UCHealth's Pulmonary Vascular Disease – Anschutz Medical Campus program and oversees the High Altitude Clinic within the PVD program.

"Many people in Colorado experience various stages of altitude sickness every day. You can get it even just going from Denver to 10,000 or 11,000 feet," said Bull, a Grand Junction native.

Though it is fairly common, it often is not identified as altitude sickness, he said, which makes it hard to establish how often it really happens.

"It is difficult to put exact numbers to this," Bull said, although "reported incidence in visitors sleeping 8,000 feet or higher is between 15 and 40 percent. The incidence depends on how high people are going (and from what starting altitude) and how fast they ascend."

This is a picture of Dr. Todd Bull, medical director of the UCHealth Comprehensive Lung and Breathing Program.
Dr. Todd Bull, medical director of the UCHealth Comprehensive Lung and Breathing Program

Milder symptoms include headache, insomnia and nausea, but victims can also suffer more serious consequences.

Altitude sickness can become acute mountain sickness, which includes cerebral edema (HACE) or pulmonary edema (HAPE), both of which can be life-threatening, he said.

The risk factors are related to rate of ascent.

"If someone comes from Florida or Texas and goes right up to Winter Park or Vail, it's more likely to happen than if they acclimate more slowly," he said. If coming from sea level, he suggested the visitor stop in Denver or Colorado Springs or somewhere along the Front Range for a night to acclimate to that altitude first. About 24 hours should be sufficient.

"That helps decrease the incidence and severity," he said.

He also suggested avoiding significant alcohol intake during the first 24 to 48 hours, because it can exacerbate the problem. Also avoid sedatives, such as benzodiazepines—"They can sometimes worsen it, as well."

Who gets altitude sickness ?

There's no definitive answer to that, he said. It doesn't seem to be related to age or sex, although people with underlying heart and lung issues may be more vulnerable.

"Other than that, there doesn't seem to be any other pre-defining risks we can identify at this point," Bull said, though it is an active area of investigation at the University of Colorado. "And if you've had it before, the likelihood of getting it again is higher."

A person looks at mountains from a nearby peak. Many people in Colorado experience various stages of altitude sickness every day.

The principle behind altitude sickness is simple, though there are many aspects that remain poorly understood.

"What's really going on here is you see lower levels of oxygen and air pressure—almost anyone can be vulnerable, given the right conditions. There is local vasoconstriction due to local hypoxia (or low oxygen). This can induce both the mild forms of the condition and also the more severe effects. And the faster and higher you go, the higher the risk."

UCHealth has a High Altitude Clinic specifically for the assessment of altitude sickness.

"Patients from all over the world come here," he said. "We've had patients who have tried to climb Everest and couldn't who are looking for help. "

In fact, he added, "Our cardiovascular and pulmonary research program helped define much of what we now know about the pulmonary vascular effects of high altitude."

Are you less likely to experience problems at 10,000 feet if you already live at 5,000 or 6,000 feet?

"We are less likely. People who come here from lower altitudes are more susceptible, of course," he said. Visitors can even get altitude sickness on the Front Range, but the symptoms are usually mild and don't last long. "Serious issues really rarely occur at this altitude."

How can I prevent altitude sickness?

Hydration: "Staying hydrated is good and avoid alcohol at first."

Acclimation: Go up in increments, allowing the body time to adjust to each level before moving up to the next.

Exertion: "As you are acclimating, limiting your level of exertion can help. Also, get plenty of rest."

Medications: "There are medications we can give to patients who we think are high risk. Discuss this with your physician."

Oxygen: "If the situation is acute, then oxygen can be administered."

Descent: "Get back to a lower altitude. This is the most important and most effective treatment always. Getting to a lower altitude is most imperative in severe cases—and oxygen should be administered as a temporizing measure at the same time."

To learn more about the High Altitude Clinic offered through the Comprehensive Lung and Breathing Program in Metro Denver, call 855.586.4824.