Pulmonary hypertension with lung pressure of 48 is that treatable and considered mild?

Mild to moderate : Mild to moderate phtn. Reversibility depends on etiology (underlying cause) so talk to your physician

Mild PH: Pulmonary hypertension (ph) is often first detected by echocardiogram which estimates the pulmonary artery systolic pressure. The diagnosis is confirmed by right heart catheterization which measures mean pulmonary artery pressure and resistance. I don't know which pressure you are referencing. Nonetheless, you need to discuss the significance with your physician.