My cast is a little tight so does lack of blood flow produce swelling?

Contact your doctor: You need to consult your treating doctor. If you notice a lot of pain or increased swelling, your doctor will probably want to examine you and possibly bivalve or replace your cast with one that does not have too much pressure. Increased compartment pressures can sometimes cause this problem, or it could be normal. When a cast is too tight, it can cause skin problems.