Good evening doctors. i have pain on the bottom of my thighs especially when sitting..at times it is very difficult to find a comfortable sitting position. what might be causing this? could it be more related to a heart issue or dvt or sciatica?

It really depends on other symptoms you may be having to say whether or not it could be heart disease-like edema, shortness of breath, etc. This is not a typical place to have a blood clot but DVTs can be asymptomatic so an ultrasound would be needed to rule that out. Sciatica is possible based on your description, especially if you also have back pain and the pain shoots down your leg. See doctor