Gout is a type of arthritis that causes painful and stiff joints, commonly in the big toe. It occurs when there is a buildup of uric acid in the body, which can then form needle-shaped crystals in and around the joint, leading to inflammation and arthritis of the joint. Gout symptoms come and go in flares called gout attacks, which can be extremely painful and incapacitating. The most common symptom of gout is pain in the affected joint, which can be intense and sudden, often waking the person up in the middle of the night. The affected joint is hot, swollen, and so tender that even the weight of a bedsheet on it may seem intolerable. Gout most commonly affects the joint at the base of the big toe, but it can also affect other joints in the body, such as the ankle, knee, and fingers. Gout can be diagnosed through a medical history, physical exam, and lab tests, and treatment options include medications to lower uric acid levels and manage symptoms. If left untreated, gout can lead to complications such as small lumps forming under the skin, joint damage, and kidney stones.