Polyuria is not necessarily diabetes mellitus, there are several diseases that can lead to symptoms of polyuria: first, diabetes mellitus, patients with elevated urinary glucose will produce osmotic diuresis, urine volume increased significantly, accompanied by thirst, fatigue, polyphagia, easy to hunger, weight loss and so on. Second, hypercalcemia, elevated calcium in the urine will also produce osmotic diuretic effect, resulting in polyuria. Third, patients with long-term hypokalemia, long-term hypokalemia leads to renal tubular epithelial cell damage, so that the urine concentration function is impaired, so the patient will also appear polyuria symptoms. Fourth, uremia, due to the thalamus and pituitary gland damage after antidiuretic hormone secretion obstacles, so that the urine concentration function is impaired, so the symptoms of polyuria will occur.