High Altitude Simulation Test, Vienna, VA

High Altitude Simulation Test (HAST) in Vienna, VA

If you have a lung or heart condition and are planning to travel by airplane or visit a high-altitude destination, your doctor may recommend a High Altitude Simulation Test (HAST). At NOVA Pulmonary Critical Care and Sleep Associates in Vienna, VA, we can evaluate how your oxygen level responds to conditions similar to those experienced during commercial air travel and help determine whether supplemental oxygen may be appropriate.

NOVA Pulmonary Critical Care and Sleep Associates

📍 Vienna Office
124 Park Street SE, Suite 203
Vienna, VA 22180
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📞 571-367-0000

Office Hours:

Mon – Fri: 9:00AM – 5:00PM
Sat & Sun: Closed

What Is a High Altitude Simulation Test?

A High Altitude Simulation Test, also called HAST or hypoxia altitude simulation testing, is designed to simulate the reduced oxygen conditions experienced at higher altitudes.

Although commercial aircraft cabins are pressurized, cabin pressure during flight is generally lower than at sea level. For most healthy travelers, this change is well tolerated. However, people with certain pulmonary or cardiovascular conditions may experience a more significant decrease in blood oxygen levels.

During HAST, you breathe a specially prepared gas mixture containing a lower concentration of oxygen—typically approximately 15% oxygen—to simulate conditions similar to those encountered in an airplane cabin at cruising altitude.

Your oxygen level and other important measurements are monitored throughout the test.

Who May Need HAST Testing?

Your pulmonologist may consider a High Altitude Simulation Test if you have an underlying condition that could affect your oxygen level during air travel or at higher elevations.

HAST may be considered for patients with:

• COPD or emphysema
• Pulmonary fibrosis
• Interstitial lung disease (ILD)
• Pulmonary hypertension
• Cystic fibrosis
• Chronic respiratory disease
• Reduced resting or exertional oxygen levels
• A history of breathing difficulties during previous flights or high-altitude travel
• Other pulmonary or cardiovascular conditions that may affect oxygenation

Not everyone with a lung condition requires HAST. Your physician can determine whether the test is appropriate based on your medical history, current oxygen levels, symptoms and travel plans.

What Happens During a HAST?

The test is performed in a controlled medical setting. You breathe a low-oxygen gas mixture intended to approximate the oxygen conditions experienced in a pressurized aircraft cabin.

During the test, your medical team may monitor:

• Blood oxygen saturation
• Heart rate
• Breathing and respiratory symptoms
• Your response to the simulated altitude conditions

In some situations, additional measurements such as an arterial blood gas may be recommended.

If your oxygen level falls below an appropriate range, supplemental oxygen may be introduced as part of the evaluation. This can help your physician assess whether oxygen may be needed during air travel and, when appropriate, what level of supplemental oxygen should be considered.

Why Is Oxygen Testing Before Air Travel Important?

At higher elevations, the amount of available oxygen decreases. Someone who has acceptable oxygen levels at sea level may experience lower oxygen saturation during a flight.

For people with certain pulmonary conditions, evaluating this response before traveling can help physicians make individualized recommendations and reduce uncertainty about oxygen needs during a flight.

HAST provides information about how your body responds to a simulated high-altitude environment rather than relying solely on your resting oxygen level.

Planning Air Travel With a Lung Condition

If testing indicates that supplemental oxygen may be appropriate during your flight, your physician can discuss the results with you and provide recommendations based on your individual situation.

Airlines have their own requirements regarding portable oxygen concentrators and medical documentation. Patients who may require oxygen should contact their airline well before traveling to learn about its current policies and approved equipment.

High Altitude Simulation Testing in Vienna, VA

At NOVA Pulmonary Critical Care and Sleep Associates, our pulmonary specialists provide comprehensive evaluation and testing for patients with respiratory conditions throughout Vienna and Northern Virginia.

If you have COPD, pulmonary fibrosis, interstitial lung disease, pulmonary hypertension or another condition that may affect your oxygen level, talk with our pulmonary team before upcoming air travel or travel to a high-altitude destination.

Contact our Vienna, VA office to schedule a pulmonary evaluation and find out whether a High Altitude Simulation Test (HAST) may be appropriate for you.

Directions & Parking Information

Our Vienna office is located on Park Street SE near the Vienna Community Center and historic downtown Vienna.

Free parking available near the building
Elevator access to Suite 203
Easily accessible from Route 123 and I-66
Minutes from Tysons Corner

If you need assistance locating our office, please call and our staff will guide you.

Frequently Asked Questions

What does a High Altitude Simulation Test measure?

HAST evaluates how your blood oxygen level responds when you breathe a reduced-oxygen gas mixture designed to simulate conditions similar to those experienced during commercial air travel.

Why can oxygen levels decrease during a flight?

Commercial aircraft cabins are pressurized, but cabin pressure is lower than typical sea-level atmospheric pressure. This results in less available oxygen and can cause blood oxygen levels to decrease.

How much oxygen do you breathe during a HAST?

The test commonly uses a gas mixture containing approximately 15% oxygen to simulate the lower oxygen availability associated with an aircraft cabin at cruising altitude.

Does everyone with COPD need a HAST before flying?

No. Many people with COPD can travel without supplemental oxygen. Your pulmonologist can consider your oxygen levels, disease severity, symptoms and medical history to determine whether HAST is appropriate.

Can HAST determine whether I need oxygen on an airplane?

HAST can provide your physician with information about how your oxygen level responds to simulated altitude conditions. If your oxygen level decreases significantly, your physician can determine whether supplemental oxygen may be appropriate during air travel.

Should I have HAST if I already use supplemental oxygen?

Patients who already use oxygen should discuss their travel plans with their pulmonologist. Your oxygen requirements during air travel may differ from those at home, and your physician can determine what evaluation is appropriate.

How should I prepare if I need oxygen during my flight?

Contact your airline in advance. Airlines have specific policies regarding portable oxygen concentrators, approved devices, batteries and medical documentation. Requirements can vary between airlines.

NOVA Pulmonary Critical Care and Sleep Associates is committed to providing excellent care in all aspects of Pulmonary Medicine and Sleep Disorders. With offices located in Lansdowne and Dulles, South Riding, we offer care for the entire Northern Virginia region, serving locations from Chantilly, Fairfax, Vienna, Centreville, Manassas, Gainesville to Reston, Sterling, Leesburg, Ashburn, Brambleton, Purcellville and more.