Insights. Your PAH Resource.
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Evaluating PAH

Treatment for pulmonary arterial hypertension (PAH) depends on the needs of each individual and the severity of his or her PAH. The most commonly used measures of severity are WHO functional class (WHO stands for World Health Organization) and 6-minute walk distance.

What is my WHO functional class?

After talking to you about your symptoms, your doctor will determine your WHO functional class.

WHO functional class

What is the 6-minute walk distance?

The 6-minute walk distance is a simple tool your doctor can use to gauge your functional capacity while you exercise based on how far, or the distance, you walk. By asking you to walk at a brisk pace for 6 minutes in a designated area at the office before you begin therapy, and then again at each appointment, your doctor can see how you are responding to treatment—and make adjustments as needed.

6-minute walk distance