When I Sit On Hard Surfaces For Too Long Hard

when i sit on hard surfaces for too long hard lumps develop on my butt cheeks and the same happens when i am on my feet for too long the lump appears on the bottom off my feet and my feet hurt....these lumps sometimes appear on other parts of my body depending on the type of clothing i wear and not only do they hurt but they itch....i do have a problem with circulation and i am wondering if this is what is causing the hard lumps.