Can knee joint pain hurt behind my knee? got a bulge there.

Yes: A lump in the back of the knee is usually a baker's cyst. The cyst is often a result of a torn cartilage or arthritis which allows joint fluid to escape and form a sack. It the pain persists, see a physician.

Baker's cyst: Swelling behind knee may be baker's cyst. Knee responds to injury/irritation with increased joint fluid production. Such as meniscal tear of cartilage injury. This increased joint fluid can accumulate as a cyst behind the knee which can be painful. Think of the cyst as a manifestation of problems elsewhere in the knee.