Joint swelling, or edema, occurs when fluid accumulates in or around a joint, leading to an increase in size and sometimes causing pain, stiffness, and reduced mobility. This condition can be caused by various factors, including injury (such as sprains or fractures), inflammatory conditions (like arthritis or gout), infections, or chronic conditions like heart failure or kidney disease. The swelling is often accompanied by redness, warmth, and tenderness in the affected area. Treatment typically involves addressing the underlying cause, using methods like rest, ice, compression, elevation, medications, or physical therapy to manage symptoms and improve joint function.