Blood acidity is also known as high blood acid, because blood acid is blood uric acid, so it can also be expressed as high blood uric acid. The following diseases are the causes of blood acidity: 1. Hyperuricemia Hyperuricemia, also known as gout, is a group of diseases caused by disorders of purine metabolism, which is clinically characterized by hyperuricemia and the resulting recurrent attacks of gouty acute arthritis, gouty stone deposits, gouty chronic arthritis and joint deformities, often involving the kidneys to cause chronic Interstitial nephritis and uric acid kidney stone formation. In primary cases, the cause of the disease is not elucidated, except for a few enzyme defects, and is often associated with hyperlipidemia, obesity, diabetes mellitus, hypertension, arteriosclerosis and coronary heart disease, and is a genetic disease. The secondary cause can be caused by kidney disease, blood disease and drugs and other causes. Gout is a recurrent inflammatory disease caused by increased purine biosynthesis, excessive production of uric acid or poor uric acid excretion resulting in elevated uric acid in the blood and deposition of urate crystals in the synovial membrane, bursa, cartilage and other tissues. The disease is characterized by the presence of bifocal monohydrate urate crystals in joint fluid and gout stones. The clinical features are: hyperuricemia and characteristic acute arthritis due to urate crystals and deposition, gout stones, interstitial nephritis, and in severe cases, joint deformity and dysfunction, often accompanied by uric acid urinary tract stones. Most commonly seen in obese middle-aged and elderly men and postmenopausal women. 3, gouty arthritis Gouty arthritis is due to uric acid deposition in the joint capsule, bursa, cartilage, bone and other tissues and cause lesions and inflammatory reactions, it is mostly genetic and family factors, most likely in men over 40 years of age, mostly seen in the metatarsophalangeal joint of the bunion, can also occur in other larger joints, especially the ankle and foot joints. The main manifestation is severe pain in the joint, which often occurs suddenly and unilaterally. There is significant swelling, warmth, redness and pressure in the peri-articular tissues. The diagnosis can be confirmed by a blood uric acid test. The treatment with medication has good effect. 4, hyperuricemia nephropathy Hyperuricemia nephropathy is a kidney disease with primary or secondary hyperuricemia with uric acid (or urate) deposition in the kidney, causing kidney stones, obstruction, interstitial nephritis, acute or chronic renal failure as a manifestation. 5. Gout and hyperuricemia Gout (gout) is a disease caused by disorders of purine metabolism due to hereditary or acquired causes. Its clinical features are; hyperuricemia and the resulting gouty acute arthritis recurrent attacks, gout stone deposition, gouty stone chronic arthritis and joint deformity, often involving the kidneys to cause chronic interstitial nephritis and uric acid kidney stone formation, can also be caused by uric acid stones acute renal failure. 6, gout in the elderly Gout is a heterogeneous group of diseases caused by hereditary and/or acquired excessive production and/or reduced excretion of uric acid. Its clinical features are: hyperuricemia and urate crystals, acute arthritis due to deposition, gout stones, chronic gouty arthritis, and gouty nephropathy. The above-mentioned manifestations may be present individually or in combination.