What is nocturnal polyuria?
Nocturnal polyuria literally means that you wake up at night (nocturnal) several times (poly) because you have to urinate ("uria").
What causes nocturnal polyuria?
Nocturnal polyuria occurs in both men and women. It becomes more common as people age.
Nocturnal polyuria is caused by the following:
- Congestive heart failure — A condition where the heart muscle weakens and can not pump blood efficiently throughout the body. If the heart can not pump efficiently, fluids can build up in your extremities (eg, legs). Swollen ankles are one sign of heart failure. During the night, your body absorbs this excess fluid, changing it into urine, and creating a need for you to urinate in the middle of the night.
- Hypoalbuminemia — An abnormally low blood level of albumin. Normally, albumin is the most plentiful protein in human blood and the key to the regulation of its osmotic pressure. Albumin helps blood hold on to its fluidity, so as albumin levels decrease, fluid eases out of the bloodstream and body as urine.
- Venous insufficiency — Venous insufficiency is a condition in which the flow of blood through the veins is impaired. When this happens, fluids can build up in your extremities and lead to the creation of excess urine and the need to urinate in the middle of the night.
- Excessive fluid intake, especially during the evening hours (ie, after 7 p.m.). This includes all fluids — from water to alcohol and caffeine in particular. Keep in mind that certain foods contain a lot of water too, such as salads, vegetables, fruits, rice and pasta.
- Use of long-acting diuretics, which may result in the need for you to urinate in the middle of the night.
- Sleep apnea — Sleep apnea is a sleep disorder in which breathing stops in intervals that may last from 10 seconds to a minute or longer. Sleep apnea triggers certain hormones in the heart that promote urine loss.
- Insomnia — trouble sleeping
- No known cause.
How is nocturnal polyuria diagnosed?
To diagnose nocturnal polyuria, your doctor will do the following:
- Take a detailed health history. You will be asked about your sleeping patterns, urinary problems, medical conditions and about the medications you are taking.
- Conduct a physical exam. Your heart and kidneys will be examined for any problems.
- Ask you to keep a voiding diary. You will be asked to record each time you urinate, the amount you urinate, and the amount of fluid you drink to help determine if you have a health problem.
- Order urinalysis and other screening tests to identify if you have an infection or other abnormality and to check your kidney function.
- Order other tests as needed, such as bladder scans, ultrasounds, sleep studies, urodynamic and endoscopic tests.
What can you do to help resolve nocturnal polyuria?
- Reduce the amount of fluids you consume — and particularly the amount of alcohol and caffeine — and particularly the amount of fluids consumed in the evening.
- Exercise regularly as a means to increase daytime fluid excretion — and overall health. If you have heart problems, talk with your doctor before beginning any exercise program.
- Consider wearing elastic support (compression) stockings to help reduce fluid retention and edema (swelling) in your legs.
- Put your feet up after lunch for several hours to also reduce fluid build up in your legs. Leg elevation needs to be as high as your heart to be effective.
- Take any diuretic — for example, furosemide (Lasix®) 10 mg — that your doctor may prescribe at tea time (4 p.m. to 6 p.m.). This will help you pass extra urine in the evening before bedtime.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed: 9/17/2008…#14246
