Pulmonary hypertension question. does it ever reverse itself?

Not on its own: It is a very serious condition that needs specialized treatment. Depending on the cause, if treatment is initiated early the pressures may decrease almost back to normal and symptoms improve significantly.

Sometimes: Secondary pulmonary hypertension can reverse itself if the inciting cause can be fixed before the pulmonary hypertension becomes permanent. Examples of reversal causes of pulmonary hypertension includes hypoxia (lack of oxygen) caused by asthma or obstructive lung disease, sleep apnea, or valvular diseases.