Arthrocentesis, also called joint aspiration, is a medical procedure that involves using a needle and syringe to withdraw fluid from a joint. It is primarily used to diagnose and treat joint conditions such as gout, pseudogout, and septic arthritis by analyzing the fluid for signs of infection, crystals, or other irregularities. This procedure can also help provide relief by removing excess fluid or injecting medications like corticosteroids. Joint injections, often performed alongside arthrocentesis, deliver medications directly into the joint to alleviate pain and reduce inflammation, particularly in conditions like osteoarthritis and rheumatoid arthritis. Together, these treatments play a vital role in improving joint function and easing symptoms for patients with chronic joint issues.