The reasons for the decrease in urine output due to hypertension are as follows: 1. Patients with high blood pressure will have water and sodium retention in their bodies, which will lead to a direct decrease in urine output. 2. Patients with hypertension will have abnormal sympathetic excitation, which will activate the renin-angiotensin-aldosterone system in the body, and the neurohumoral endocrine system will be disrupted, which will also lead to a decrease in urine output. 3. The kidneys are directly damaged, and the glomerular filtration rate decreases when the kidneys are decreasing, as well as the tubular reabsorption function decreases, thus further aggravating the situation of reduced urine output. 4. Patients with hypertension will also experience varying degrees of swelling, especially swelling of the feet and lower extremities, which is caused by stagnation of blood in the body circulation, resulting in a further decrease in urine output.