Polyuria does not necessarily indicate kidney disease. Polyuria is often associated with diet, diabetes mellitus, pituitary uremia, etc. In addition, kidney diseases such as acute renal failure with polyuria and tubular injury can also cause polyuria. 1. Diet: If you drink a lot of water in a short period of time, or consume fruits with high water content, resulting in increased blood volume, the kidneys will produce a large amount of urine, which is normal, and the amount of urine will return to normal after the body digests and absorbs it. 2. Diabetes: diabetic patients will drink more water because of frequent dry mouth, which will lead to more urine. Diabetic patients with increased blood sugar, will cause osmotic diuresis, which leads to patients urinate more. Diabetes mellitus can be controlled by treatments such as daily diet, exercise and medication. 3. Pituitary uremia: due to hypothalamic-pituitary pathology, the secretion of antidiuretic hormone (ADH) is reduced or lacking, the reabsorption of water by renal distal tubules decreases, and low-specific gravity urine is discharged, and the volume of urine can reach more than 5000 ml/d. 4. Renal diseases: seen in chronic nephritis, chronic pyelonephritis, glomerulosclerosis, renal tubular acidosis, drugs, chemicals or heavy metal damage to the renal tubules, but also in acute renal failure polyuria stage. Polyuria occurs when there are congenital or acquired defects in the distal tubules and collecting ducts of the kidney, decreased responsiveness to antidiuretic hormone, and decreased water reabsorption. There are many reasons for polyuria, and it is recommended that patients with polyuria should consult a regular hospital, complete the relevant examinations under the guidance of a physician, and carry out targeted treatment for different causes.