Gout: Causes

Gout is caused by an excess of uric acid in the body that deposits in a crystal form in the joints. An excess of uric acid, called hyperuricemia, can result from many factors, such as the following:

• Genetics. Twenty percent of people with gout have a family history of the disease.

• Gender and age. It is more common in men than in women and more common in adults than in children.

• Weight. Being overweight increases the risk of developing hyperuricemia and gout because there is more tissue available for turnover or breakdown, which leads to excess uric acid production.

• Alcohol consumption. Drinking too much alcohol can lead to hyperuricemia, because alcohol interferes with the removal of uric acid from the body.

• Diet. Eating too many foods that are rich in purines can cause or aggravate gout in some people.

• Lead exposure. In some cases, exposure to lead in the environment can cause gout.

• Other health problems. Renal insufficiency, or the inability of the kidneys to eliminate waste products, is a common cause of gout in older people. Other medical problems that contribute to high blood levels of uric acid include:

• High blood pressure

• Hypothyroidism (underactive thyroid gland)

• Conditions that cause an excessively rapid turnover of cells, such as psoriasis, hemolytic anemia, or some cancers

• Kelley-Seegmiller syndrome or Lesch-Nyhan syndrome, two rare conditions in which the enzyme that helps control uric acid levels either is not present or is found in insufficient quantities.

• Medications. A number of medications may put people at risk for developing hyperuricemia and gout. They include: 

• Diuretics, such as furosemide, hydrochlorothiazide, and metolazone, which are taken to eliminate excess fluid from the body in conditions like hypertension, edema, and heart disease, and which decrease the amount of uric acid passed in the urine

• Salicylate-containing drugs, such as aspirin

• Niacin, a vitamin also known as nicotinic acid

• Cyclosporine, a medication that suppresses the body's immune system (the system that protects the body from infection and disease). This medication is used in the treatment of some autoimmune diseases, and to prevent the body's rejection of transplanted organs.

• Levodopa, a medicine used to support communication along nerve pathways in the treatment of Parkinson's disease.