What should you know about left leg swollen from knee down?

Swelling may begin inside the knee and make the area below it feel heavy or tight. A sprain, ligament or meniscus injury, bursitis, arthritis, or gout can inflame the knee. A fluid-filled Baker's cyst behind the knee may also cause fullness extending downward. If the whole calf becomes swollen, warm, tender, or tight, a clinician should check causes beyond the joint, including circulation problems. The side-to-side difference, speed of onset, skin colour, and ability to walk are useful details.

Do not assume the swelling is caused by a knee condition simply because it starts near the knee. Note recent injury, long travel or immobility, fever, skin breaks, and breathlessness.

Rest from impact and keep the leg comfortably elevated when sitting. Avoid tight clothing or massage until a clinician has considered the cause, particularly if swelling is sudden or the calf is tender. A cool pack wrapped in cloth can ease an irritated joint for short periods. Arrange assessment for persistent swelling, reduced knee movement, or difficulty walking. Depending on the findings, treatment may address the knee itself; joint aspiration is one procedure clinicians may use to remove fluid or examine it. Related information includes [Knee Swelling](/symptoms/knee-swelling/) and [Joint Aspiration](/treatments/non-surgical-orthopedics/joint-aspiration/).

Seek emergency help for leg swelling accompanied by chest pain, sudden breathlessness, faintness, or coughing blood. Seek same-day care for rapidly increasing one-sided swelling, marked warmth or redness, severe calf pain, fever, a cold or pale foot, new weakness, or inability to bear weight. After an injury, urgent review is needed if the knee is visibly deformed or movement is suddenly lost.

Is the fluid coming from the knee joint or the lower leg? Do I need an ultrasound, X-ray, or another test? Should I use elevation, a brace, or a walking aid? Which symptoms require emergency help?