I've just been told i have acute synovitis and joint effusion in my left foot due to ultrasound what does it mean? what do i do about it?

NSAIDS, rest: Synovitis is inflammation of the fluid that lubricates your joints. Often caused by injury, overuse, and occasionally by virus infections. Treatment is rest and anti-inflammatory medications (NSAIDs such as ibuprofen, naproxen, etc.). Will usually resolve in a few weeks. See your doctor for fever, spreading redness, or significant change in symptoms.