Dizziness after urination, it is recommended to go to the hospital for further examination to clarify the cause: 1. If the urine is emptied from the bladder in the state of urinary retention or while holding urine, dizziness may occur, mostly due to low blood pressure. When there is a large amount of urine stored in the bladder, this is can cause an increase in bladder tension and can lead to a transient increase in blood pressure. As the urine is removed from the bladder, the bladder pressure drops abruptly, and this is when a transient drop in blood pressure can occur and dizziness can occur. If the dizziness is mild, it does not require any treatment and moderate rest is sufficient. However, if the dizziness is severe, it is necessary to go to the hospital for further examination and monitoring of blood pressure to clarify whether there is usually a relatively large fluctuation in blood pressure. 2. Ectopic pheochromocytic tissue, such as pheochromocytoma of the bladder, can stimulate the tumor to secrete too much adrenaline in the state of holding urine, which can cause an increase in blood pressure. The withdrawal of adrenaline after urination leads to a transient drop in blood pressure, at which point dizziness can occur. Ultrasound or CT examination of the bladder may reveal solid tumor tissue, and further tests such as hormone series of catecholamines and adrenaline are needed to further confirm the diagnosis.