Uric acid is the end product of purine metabolism. The saturation and concentration of uric acid in the body is about 420μmol/L (7mg/dl) at 37℃, exceeding this concentration is called hyperuricemia. When uric acid exceeds the saturation concentration, urate crystals precipitate out 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. 2, gout acute attack period: sudden single joint redness, swelling, heat and pain as the main performance, generally at night or in the morning sleep attack, the lower extremity foot joints are common, the first metatarsal toe joint is most common, can also spread to the knee, fingers, wrist, elbow and other joints. At this time, patients often feel that the joint swelling and pain is severe, as if a knife cut, insect bite, etc.. 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 can be frequent, and enlarged gout stones can gradually appear, distributed in the auricle, foot, hand, elbow and other places, which not only affect the appearance, but also exist in the joint periphery of the gout stones can erode the joint bone surface, causing chronic joint inflammation, resulting in persistent joint swelling, pain, and even joint deformity. 3, kidney disease: ① Gouty nephropathy: uric acid salt deposited in the kidneys can cause gouty nephropathy, resulting in hematuria, proteinuria, edema, anemia, hypertension, renal colic and other symptoms. (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. 4. Eye diseases: Recurrent conjunctivitis, keratitis, sclerenitis, and mild congestion of the optic disc in the fundus are often seen, and exudation, edema or exudative retinal detachment may occur in the retina. In short, long-term hyperuricemia can cause a series of serious complications, such as hypertension, diabetes, hyperlipidemia and so on, so patients must pay attention to the active treatment, to minimize the occurrence and development of adverse consequences.