There are various causes of hyperuricemia resulting from an overproduction of uric acid. These include genetic disorders with enzyme defects, drugs such as chemotherapy, diet-related disorders such as vitamin B12 deficiency, alcohol use, and medical conditions such as blood disorders and certain cancers. There are also disorders and factors that are associated with decreased uric acid clearance, including underlying kidney disease, medical conditions such as endocrine disorders, and medications such as laxatives or diuretics.