Why does my back hurt when i cough? when i sit down its hard for me to be comfortable

Many things: Sometimes benign acute back pain can cause problems like this. It just happens, but often will improve with simple measures like over the counter pain relievers, heat or cold packs, gentle exercise and time. If it does not show improvement over a week or so, see your primary provider to check for a more serious problem.

May be a disc issue: Coughing, sneezing and bearing down to have a bowel movement may cause back pain or aggravate it if there is a disc problem. Sitting also places a higher load on the discs of the lower back as compared to standing or lying down.