Answers to Frequently Asked Questions About PAH

Pulmonary arterial hypertension (PAH) is high blood pressure in the arteries of the lungs (the pulmonary arteries). These arteries carry blood from the heart to the lungs, where the blood picks up oxygen before being pumped to the rest of your body.

Over time, the arteries in the lungs of a person with PAH become narrow. This narrowing increases the pressure within the arteries and decreases blood flow from the heart to the lungs. The increased pressure can also cause further injury to the arteries. The heart must then pump harder, causing the walls on the right side of the heart to thicken and weaken.

The most common symptoms of PAH are shortness of breath and feeling tired or weak. As PAH worsens, symptoms become more severe and interfere with daily activities.

Prostacyclin class therapy is an established treatment option for pulmonary arterial hypertension (PAH). It mimics some of the effects of prostacyclin, a substance naturally produced by the body to help keep blood vessels open and working properly.

You can learn more about pulmonary arterial hypertension (PAH) through the Pulmonary Hypertension Association (PHA) and the National Heart, Lung, and Blood Institute (NHLBI).

The PHA is a leading community-based organization for patients with PAH. Its mission is to find ways to prevent and cure PAH, while providing hope and practical services to the community of people who have PAH or have a loved one with this disorder. To learn more, visit

The NHLBI is part of the National Institutes of Health (NIH), the agency responsible for conducting a majority of all federally funded medical research. The NHLBI website has easy-to-understand information about many diseases affecting the heart and lungs. Visit, and search for “PAH.”


Before you take Tyvaso, tell your healthcare provider about all of your medical conditions, including if you:

It is important to tell your healthcare provider about all the medicines you may be taking, including prescription and non-prescription medicines, vitamins, and herbal supplements, as they may affect your use of Tyvaso by increasing the risk of side effects or decreasing effectiveness. Especially tell your healthcare provider if you take any of these medicines:

The most common side effects of Tyvaso are coughing, headache, throat irritation and pain, nausea, reddening of the face and neck (flushing), and fainting or loss of consciousness. These are not all the possible side effects of Tyvaso. Tell your healthcare provider about any side effects that bother you or do not go away. Your healthcare provider may be able to help you manage the side effects.


Tyvaso is a prescription medicine used in adults to treat pulmonary arterial hypertension (PAH) (WHO Group 1), which is high blood pressure in the arteries of your lungs. Tyvaso can improve exercise ability in people who also take bosentan (an endothelin receptor antagonist, (ERA)) or sildenafil (a phosphodiesterase-5 (PDE-5) inhibitor). Your ability to do exercise decreases 4 hours after taking Tyvaso.

The effects of Tyvaso are unknown in patients under 18 years of age.


Please see the Full Prescribing Information, Patient Package Insert, and the Tyvaso Inhalation System Instructions for Use manual.

For additional information about Tyvaso, visit or call 1-877-UNITHER (1-877-864- 8437).

Call your healthcare provider for medical advice about side effects. You may report side effects to the FDA at or call 1-800-FDA-1088.

This information is provided for an informational purpose and is not intended as treatment advice. Patients should consult a healthcare professional for treatment advice.