Could I have p.A.D.? I have constant pain in my legs. Mostly my calves. Several times I have had severe symptoms of cellulitus. I have read that symptoms of pad can mimic cellulitis. I've had severe swelling in ankles and the last instance was I took off

Pain on walking? Is it both legs? If pad the pain is much worse on walking, especially uphill. Are your feet cold? Are your feet purple when you sit or stand, then pale when elevated up high? Do you have fever, pus, tenderness, red streak? Pad can be differentiated from cellulitis. Either way, you need an experienced dr.
Consult Vascular. It's important that ultrasounds evaluate the flow in both arteries and veins to determine an underlying peripheral vascular disease problem. Without proper flow, each bout of cellulitis can become difficult to treat due to inefficient flow and then becomes a vicious cycle. It can be dangerous if left untreated.
Possible. See vascular surgeon and get tested- simple, noninvasive and sort it out. Sounds more venous, than arterial.
You more . Likely have PVD thanpad. Pad implies the arteries usually such symptoms are more common in people with venous issues.
PAD or veins. Your description sounds a little more like venous leg disease especially if you sit or stand for long periods without moving your legs much. Your doctor can help determine if this is due to arteries or veins or both and will check your cardiac and renal function. There are a few other less common possibilities as well.
You . You need to get arterial ultrasounds of both legs and make hearts disease has been rulel out.
What's the cause ? Cellulitis is basically a visible inflammation (itis) of the skin and soft tissues (red, hot, swollen and tender) . It can be caused by many things including sunburn (radiation), trauma (sprained ankle) or poor vein circulation (stasis dermatitis). It need not be caused by bacteria. If you have repeated episodes of this, get to a wound care or vascular specialist, the diagnoses you have is wrong.