This study aims to learn more about how people with pulmonary hypertension (PH) related to interstitial lung disease (ILD) are doing and how they're treated. PH is when blood pressure in the lungs is too high, and ILD means the lungs are scarred and can't work properly. The study will follow patients for up to 5 years, checking their health every 6 or 12 months.

Patients will be placed in one of four groups. Some groups will have people who are taking a medicine called Tyvaso or Tyvaso DPI, and some groups will have people who aren't. Tests will check how well their lungs work, how far they can walk in 6 minutes, and may include blood tests and heart checks.

• The study will last up to 5 years with check-ups every 6 or 12 months.
• Participants may have to take Tyvaso or Tyvaso DPI and do different health tests.
• The study is for adults who can give consent and speak English or Spanish.

It's important to note if you have other types of PH or take certain medications, you may not be eligible.