There are different types of pulmonary hypertension depending on the cause.
https://www.mayoclinic.org/diseases-conditions/pulmonary-hypertension/symptoms-causes/syc-20350697

I first heard the term mild pulmonary arterial hypertension by looking at a recent echo report on the clinic patient portal - the cardiologist (EP) did not mention it. When I asked, they said they didn't address that issue and I'd need to see a lung dr. So I self-referred - he first thought maybe I had asthma causing this and prescribed an inhaler which I tried for a month and it didn't seem to make a difference. So next I knew I was prescribed oxygen during exercise and at night connected to my CPAP and he wants to do a right heart cautery to more definitively diagnosis. I was SHOCKED. I'm not at all sure this is the problem. Also just recovering (2 weeks ago) from an ablation for Afib. Yesterday I saw my primary for a severe sinus infection that has been going on for a month and she says she doesn't think I need to do the procedure because it is mild and she thinks it could be age related (I'm 81). I am thoroughly confused now. Have not used the oxygen during the day but am using it at night - can't tell a difference. I ordered a wearable O2 ring that I am going to use and track my O2 24/7 and see what it really is.