Gout is a form of arthritis caused by a build up of crystals in a joint. It most often affects the joint of the big toe, but can but it can affect other joints as well. Gout may occur in a single attack or become a recurrent problem. During acute attacks, gout can cause pain, swelling, and redness in the affected joint. Periods between acute attacks are usually symptom-free.
Gout can also create a collection of crystals under the skin called tophi. The tophi are visible lumps under the skin that can show up anywhere in the body and become tender during acute attacks.
Over time, gout can cause permanent damage to the affected joints and the kidneys. Fortunately, these long term factors are less likely to occur with proper treatment. The earlier gout is detected and treated, the better it can be managed.
Types of Gout
- Elevated levels of uric acid in the blood (hyperuricemia), but no other symptoms.
- Present before the first gout attack.
Acute gout (gout attack):
- Chronically increased uric acid levels result in the deposit of uric acid crystals in the joint spaces.
- Symptoms develop quickly, usually overnight and after some stimulus or trigger.
- Will usually resolve within 3 to 14 days, even without treatment.
- A symptom-free time between attacks.
- Crystals usually present in the joint.
- Low-level inflammation may damage the joints.
Chronic tophaceous gout:
- Occurs in people with gout and uric acid levels that remain high for a long time.
- Attacks become more frequent and the pain may not resolve completely between episodes.
- Joints may become damaged and be persistently stiff and swollen.
- Crystal may build up in the skin (tophi) or around the joints as subcutaneous nodules.
- The kidneys may be damaged.
Causes of Gout
Gout is caused by the build-up of uric acid crystals in and around a joint. Crystals often form because of high levels of uric acid in the blood.
Uric acid is created in the liver and released into the blood during the breakdown of a substance in food called purines. The uric acid is then filtered out of the blood through the kidneys and passes out of the body through urine. Higher than normal levels of uric acid in the blood may be caused by:
Increased production of uric acid from:
- Excess consumption of foods high in purines like steak, seafood, and organ meats
- Certain medications, such as cytotoxic agent (chemotherapy) or vitamin B12
Decreased excretion of uric acid from:
- Impaired ability to clear the uric acid in the kidneys, which may occur with kidney damage or disease
- Consumption of foods such as alcohol or sugary drinks
- Certain medications, such as diuretics, salicylate containing medications (like aspirin), niacin, or levodopa
- Medical conditions, such as high blood pressure, obesity, hypothyroidism, Kelley-Seegmiller syndrome or Lesch-Nyhan syndrome
- Reviewer: Michael Woods, MD, FAAP
- Review Date: 02/2017 -
- Update Date: 02/24/2017 -