Uric acid is the end product of purine metabolism and is mainly produced by the enzymatic breakdown of nucleic acids and other purine analogues from cellular metabolism and purines from food. The saturation and concentration of uric acid in the body at 37℃ is about 420μmol/L (7mg/dl), and exceeding this concentration is called hyperuricemia. When uric acid exceeds the saturation concentration, urate crystals will be precipitated and can be directly deposited in joints and surrounding soft tissues, kidney tubules and blood vessels, etc. Long-term hyperuricemia can cause a series of serious diseases. 1, gout: long-term hyperuricemia is the main cause of gout, gout asymptomatic period, the patient may not have any discomfort, only a continuous or fluctuating increase in blood uric acid, this period can last for several years or decades. The acute attack of gout is characterized by sudden onset of single joint redness, swelling and pain, mostly at night or in the morning during sleep, mostly in the joints of the lower extremities, the first metatarsal phalangeal joint is the most common, but can also spread to the knees, fingers, wrists, elbows and other joints. At this time, the patient often feels that the joint swelling and pain is severe and unbearable, like a knife cut or insect bite. However, most of them are self-limiting, even without the use of drugs, the joint symptoms can be relieved by themselves within a few days or 2 weeks, or even disappear. Gout stones: If the condition is not well controlled, acute gout may occur frequently and enlarged gout stones may gradually appear in the auricle, foot, hand, elbow and other places, affecting the appearance. Gout stones present around the joints can erode the bone surface of the joints and cause chronic joint inflammation, resulting in persistent joint swelling, pain, and even joint deformity. 2. Kidney: ① Gouty nephropathy: uric acid salt deposited in the kidney can cause gouty nephropathy, leading to symptoms such as hematuria, proteinuria, edema, anemia, hypertension, and renal colic. (ii) Uric acid nephrolithiasis: It can vary from no obvious symptoms to manifestations such as renal colic, hematuria, difficulty in urination, hydronephrosis, pyelonephritis or perinephritis. ③Acute renal failure: A large number of urate crystals block the renal tubules, renal pelvis and even ureter, and the patient suddenly develops oliguria or even anuria, which can develop into acute renal failure. 3. Eye: Recurrent episodes of conjunctivitis, keratitis and sclerenitis can occur. The optic disc in the fundus is often mildly congested, and the retina can develop exudation, edema or exudative retinal detachment. Therefore, long-term hyperuricemia can cause a series of serious diseases, patients must pay attention to the active treatment to minimize the development of adverse consequences.