Who needs medical clearance in order to fly?

Part 2. Pts with recent hospitalization. Pts with recent heart attacks ( 6 months). Pts with not well controlled diseases like hypertension, diabetes. Pts with significant pain, and more would be better if they consult before traveling by plain or long distances by car or if they travel to a high altitude city.
Multiple. Patients that require oxygen. Patients with risk factors for clots in the legs or lungs. Pts who may have active infectious disasses who can transmitt the disease in small compartments like airplanes. Long flies or long drives require everybody to move the legs ( calves) often. Some pts may get Lovenox (enoxaparin) injection before traveling if high risk for clots. Pregnant women need to be cleared.Part 2.