My patella is tender to touch, and hurts and pops when the knee is bent. there isn't any noticeable swelling. but there is pressure around patella.

Get evaluated: Patello-femoral knee pain (pain behind the knee cap) can have multiple causes including but not limited to trauma, infection, and neoplasm. Patello-femoral pain can be very common and some rest, NSAIDS, and therapy are usually helpful. A thorough history and physical followed by diagnostic imaging can help get the answers and treatment you might need.

Needs to be checked: It needs to be checked as it may be due to 1patellofemoral pain syndrome.Patellofemoral joint is where patella joins femur 2kneecap tracking 3chondromalacia patella which is damage to cartilage to back of knee cap 4tendinitis or osteoarthritis you need a thorough examination and if indicated mau need an MRI or xray exam to make the diagnosis and you may need nsaids and/or physical therapy depends.