People keep telling me this is pretty serious. i have just noticed swelling up my shins from long hours at pc. no prior problem so what would a doctor do for this?

I must admit I have: No idea what "long hours of pc" might be (personal computer?), but "swelling" may be edema, fluid accumulated. Push and hold for 30 - 60 seconds, it should leave a mark (pitting edema). This can be a sign of heart or kidney disease. The doctor would take a history, examine you, perhaps do blood, x-ray and urine tests to start, and an ekg. Go.