What should you know about fall on knee swelling?

A direct impact can bruise soft tissue or irritate a bursa. Swelling that appears quickly may reflect bleeding or fluid inside the joint, while delayed swelling can occur as inflammation develops. A twist during the fall may injure the ACL or meniscus; these conditions are described in [ACL Tear](/conditions/acl-tear/) and [Meniscus Tear](/conditions/meniscus-tear/). Other causes of a swollen knee include arthritis, gout, or a Baker’s cyst, so the swelling itself does not identify one diagnosis. A clinician will assess motion, stability, tenderness, and weight-bearing ability.

For the first period after injury, protect the knee from activities that increase pain, use a wrapped cold pack for short intervals, and elevate the leg when resting. Gentle movement within comfort can reduce stiffness, but do not force bending or test the knee with running or jumping. Use a walking aid only if it has been fitted or explained safely. Arrange assessment if swelling is substantial, movement remains limited, or symptoms are not settling. A clinician may consider [Joint Aspiration](/treatments/non-surgical-orthopedics/joint-aspiration/) when fluid needs evaluation or pressure relief.

Go to urgent care for an obvious deformity, inability to bear weight, severe pain, a locked knee, numbness, a cold or pale foot, or rapidly increasing swelling. Seek prompt medical attention for fever, spreading redness, or warmth that is not explained by the impact. These features can signal a fracture, significant internal injury, or infection and need examination rather than home observation.

Ask whether you need an X-ray or other imaging, which structures may be injured, and how much weight-bearing is appropriate. Ask when to begin rehabilitation, which pain measures are suitable for you, and which changes should trigger a return visit.