Swelling After a Bruised Knee

A mild injury may remain tender yet allow careful walking. Rapid swelling, inability to straighten the knee, instability, or difficulty bearing weight can point to a deeper joint or bone injury and should be assessed.

A direct knock may bruise the skin, fat, or muscle over the kneecap. Fluid can also gather inside the joint, making the knee look full around or above the kneecap and limiting bending. Swelling over one small, tender spot may involve a fluid-filled bursa. Twisting during the incident, a pop, locking, or giving way raises concern for structures such as a ligament or meniscus rather than an isolated surface bruise.

Reduce activities that increase pain, especially kneeling, running, deep squats, and twisting. Apply cold through a cloth for brief sessions, rest the leg raised, and use comfortable compression if it does not cause numbness or colour change below the knee. Gentle bending and straightening can help prevent stiffness when movement is tolerable. Do not force a locked knee or repeatedly test whether it will give way. Pain medicine may not suit everyone, so check with a pharmacist or clinician if you have other conditions or take regular medicines.

Get urgent care if the knee looks deformed, swelling develops quickly after injury, you cannot bear weight, or the joint is locked and cannot straighten. Prompt assessment is also needed for a hot, red knee with fever or feeling unwell, an open wound over the joint, or a cold, pale, numb foot. Book an examination if swelling persists, movement remains restricted, the knee repeatedly buckles, or pain interferes with sleep or everyday walking.

Ask which tissue seems injured, whether imaging is likely to change care, and how much weight the leg can safely take. If there is substantial joint fluid, ask what may have caused it and whether removing fluid would help diagnosis or comfort. Clarify which exercises are appropriate and what milestones should guide a return to driving, work, or sport.