What Is Gout?
Gout is one of the most painful rheumatic diseases. Gout results from deposits of needle-like crystals of uric acid in connective tissue, joint spaces, or both. These deposits lead to inflammatory arthritis, causing swelling, redness, heat, pain, and stiffness in the joints. Gout accounts for about 5% of all cases of arthritis.
Pseudogout is sometimes confused with gout because it produces similar symptoms. However, in pseudogout, deposits are made up of calcium phosphate crystals, not uric acid.
Uric acid is a substance that results from the breakdown of purines, which are part of all human tissue and are found in many foods. Normally, uric acid is dissolved in the blood and passed through the kidneys where it is eliminated in the urine. If the body increases its production of uric acid or if the kidneys do not eliminate enough uric acid from the body, levels of it build up in the blood (a condition called hyperuricemia).
Hyperuricemia also may result when a person eats too many high-purine foods. Hyperuricemia is not a disease and by itself is not dangerous. However, if excess uric acid crystals form as a result of hyperuricemia, gout can develop. The excess crystals build up in the joint spaces, causing inflammation. Deposits of uric acid, called tophi, can appear as lumps under the skin around the joints and ear rim. In addition, uric acid crystals can collect in the kidneys and cause kidney stones.