Nocturnal polyuria

Synonyms: Excessive nighttime urination

Medical Specialties: Family practice, Internal medicine, Urology

Clinical Definition

Nocturnal polyuria is an excessive volume of urination at nighttime. Etiologies include, excessive fluid intake (especially of caffeine or alcohol), congestive heart failure, renal insufficiency, and other conditions. Diagnosis depends on a careful health history, physical exam, evaluation of a voiding diary, tests such as urinalysis and urodynamic tests; treatment includes treating underlying disease and suggesting lifestyle modifications such as taking diuretics earlier in the day.

In Our Own Words

Nocturnal polyuria is not just urinating a lot at night, but making more urine than is normal during nighttime. It’s a nighttime urinary output that is a greater percentage of the 24-hour urine output than is normal. It can be caused by congestive heart failure, drinking too many beverages at night, the use of diuretics at night, or sleep apnea. Bladder storage problems in contrast, can result in more trips to the bathroom at night, but each with smaller volumes voided. Uncontrolled diabetes can result in daytime and nighttime polyuria.


Diagnosis is made after a careful history, looking at the patient's voiding diary, considering fluid intake and underlying disease. Lifestyle modifications, such as restricting fluid intake later in the day and taking diuretic (blood pressure) medication earlier can help.

Relevant Conditions
  • Coronary artery disease (heart disease)
  • Diabetes
  • Hypertension (high blood pressure)
  • Overactive bladder
Side Effects
  • Frequent urination at night
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