Once joint effusion occurs, it may be associated with joint pain, localized swelling, limited joint movement, and may even be accompanied by other systemic symptoms and manifestations such as fever, and so on. As you already know, joint effusion is a kind of manifestation, and there are different specific reasons for its occurrence, such as joint degeneration, trauma, infection, manifestation of other systemic diseases in the joints, etc., all of which need to be treated in accordance with the reasons for their occurrence, and symptomatic treatments can be taken at the same time if the local symptoms are obvious. Such as joint degeneration caused by joint effusion, generally before there is obvious joint strain activities, such as knee arthropathy patients recently climbed a mountain or after excessive exercise; such as trauma causes generally appear soon after the injury or within a few days of the slow appearance, may suggest that intra-articular injuries need to be diagnosed and treated. Patients with infections may require anti-infective treatment; patients with other systemic diseases are even more important to treat the primary disease. Regardless of the cause of the joint effusion, generally speaking, the first thing we need to do is to rest, localized braking of the joints, and in cases where the diagnosis is not clear, avoiding rubbing, hot compresses, and high temperature physical therapy, as these measures may exacerbate the inflammatory response and lead to worsening of the symptoms. Patients with joint effusion in the lower limbs should avoid or reduce weight-bearing because, after all, temporary braking is the most basic and important measure to reduce the inflammatory response when the cause is not clear. Finally, it is still recommended to go to the hospital as early as possible for examination is the best policy.