Gout is a type of arthritis in which small crystals form inside and around the joints, causing sudden attacks of severe pain and swelling. Gout can affect any joint in the body, including the knee, and it is estimated that between one and two in every 100 people suffer from it. Gout in the knee can cause redness, swelling, and a hot sensation in the affected joint. The knee may be very tender or extremely painful to touch or move, and the symptoms tend to come on suddenly, often starting in the early morning and reaching their worst point within 24 hours. Gout in the knee can be triggered by high levels of uric acid in the blood, which can cause urate crystals to accumulate in the joint. People who previously injured their knee joint could be more likely to develop gout in their knee, as the injured joint can develop degenerative arthritis or osteoarthritis earlier than it would with aging alone. If left untreated, gout can continue to cause severe pain and may spread throughout the body, resulting in permanent damage to the joints and bones. It is important to seek medical advice if you experience sudden, intense pain in a joint, especially if you have a fever and a joint is hot and inflamed, which can be a sign of infection.