Most people typically urinate four to eight times a day. Needing to go more than eight times a day or waking up in the night to go to the bathroom more than once in the night is considered frequent urination. Though the bladder can often hold as much as 600 ml of urine (about 2 ½ cups), the urge to urinate is usually felt when the bladder contains about 150 ml of urine (just over ½ cup).
Urinary tract infection (UTI) or bladder infection: The lining of the urethra (the tube that carries urine from the bladder out of the body) and bladder becomes inflamed and irritated due to byproducts of infection (blood, white blood cells, bacteria).
This irritation of the bladder wall causes the urge to empty the bladder frequently (called frequency). The amount of urine during each emptying is often smaller than the usual amount.
Diabetes mellitus and diabetes insipidus: An early symptom of both type 1 and type 2 diabetes can be frequent urination, as the body tries to rid itself of unused glucose (blood sugar) through the urine.
Diabetes can also damage the nerves that control the bladder, causing frequent urination and difficulty controlling your bladder Diuretic use: Medications used to treat high blood pressure or fluid buildup work in the kidney and flush excess fluid from the body, causing frequent urination.