Synovial fluid is produced by the synovium, which is a soft and thin membrane that lines the joint capsule. The synovial fluid is a viscous solution found in the cavities of synovial joints and acts as a joint space lubricant of articular cartilage and nutrient source through diffusion for surrounding structures including cartilage, meniscus, and labrum. The fluid is generated from an ultrafiltrate of blood plasma which is regulated by synovium. The synovial fluid contains molecules that provide low-friction and low-wear properties to articulating cartilage surfaces. The fluid is mainly composed of hyaluronan, lubricin, proteinase, collagenases, and prostaglandins. Hyaluronic acid and lubricin are made by the fibroblast-like synoviocytes, which are a cell type in the synovial membrane. The synovial fluid also contains molecules, mainly glycosaminoglycans, which are made within the joint. These molecules include hyaluronic acid and other proteoglycans such as the ‘superficial zone protein’ and lubricin. In case of joint inflammation, swelling or redness, a synovial fluid analysis may be done to detect any traces of lactic dehydrogenase, uric acid, and protein which can be held responsible for inflammation.