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 hazards. 1, gout: gout asymptomatic period, generally refers to the early patients may not have any discomfort performance, only the blood uric acid persistent or fluctuating elevation, this period can last for several years or decades. The acute attack of gout is characterized by sudden onset of single joint redness, swelling, heat and pain, mostly at night or in the morning during sleep, mostly in the joints of the lower extremities, the first metatarsophalangeal joint is the most common, and 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 within a few days or 2 weeks, or even disappear. 2. Gout stones: If the condition is not well controlled, acute gout can have frequent attacks, and enlarged gout stones can gradually appear, distributed in the auricles, feet, hands, elbows 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: ① Gouty nephropathy: uric acid salt deposited in the kidney can cause gouty nephropathy, resulting in 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. 4, eye: can be recurrent conjunctivitis, keratitis, sclerenitis, or eye muscle can appear inflammatory edema, the fundus optic disc is often mildly congested, the retina can occur exudate, edema or exudative retinal detachment. In conclusion, high blood uric acid is mainly caused by two types of causes: increased uric acid production and reduced uric acid excretion.