Nocturia - “I Have to go too often at night”

May people are bothered with the need to urinate too often at night.

How does the body make urine? How does the urinary system work?

The urinary tract begins with the kidneys. The kidneys, one on each side, sit high in the upper abdomen partially underneath the rib cage. They filter the blood to extract excess waste products and fluid to form the urine. Urine, once formed in the kidneys, travels through a tube on each side, the ureter, down to the bladder. Urine is constantly being made by the kidneys and transported through the ureters into the bladder.

The bladder stores urine until full and then empties to the outside through the urethra, the urinary pathway to the outside. The urinary system is the same in both men and women from the kidneys to the bladder. In men, the prostate, a gland that is part of the reproductive system, forms the first part of the pathway.

How much fluid do the kidneys make?

In a young, healthy adult, the kidneys typically produce 8-10 ounces of urine during the night. By age 40, the kidneys begin to make more fluid at night. For some people, the kidneys may make 40 ounces, or more, of urine overnight.

How much does the bladder hold?

A normal bladder can usually hold about 8-12 ounces of urine.
By age 40, the bladder gets “smaller”. It may only hold 4 to 6 ounces of urine before there is the sensation of the need to go.

Why do I have to get up so much at night to pee?

A person voids more often at night if the kidneys make more than 8-12 ounces of urine, or if the bladder holds less than 8 ounces. Usually, there is a combination of both.

Why do the kidneys make more fluid at night?

During the day, fluid accumulates in a person’s legs and ankles. At night, when the person lies down flat to sleep, the body reabsorbs fluid. The kidneys get rid of this extra fluid and make more urine.

Why does the bladder hold a smaller amount of fluid?

The bladder gets smaller with age. The bladder loses elasticity, and it can’t stretch to hold more urine. When the bladder is smaller, the storage capacity decreases, and the bladder needs to empty more often.

In men, the prostate enlarges. As the prostate enlarges, it may block the urethra, the urinary pathway from the bladder to the outside. When the bladder muscle works harder, the bladder muscle gets thicker, less elastic and smaller. The bladder holds less.

Treatment of the enlarged prostate may reduce the number of times a man awakens at night to void.

How can you tell which it is? More fluid? Or smaller bladder?

The patient can keep a voiding diary. The patient records the time and amount of each void during the night.

Is there anything that will help if there is an increase in the amount of urine made?

Measures available to reduce the volume of urine produced by the kidneys overnight include evening fluid restriction and leg elevation. Leg elevation may allow some of the fluid which accumulates in the legs during the day to be reabsorbed while the patient is still awake and reduce the amount of urine made once the patient is asleep.

Is there anything to help if the bladder is smaller?

Treatment can be directed to the bladder to try to improve storage capacity (how much it can hold).

In men, treatment of the enlarged prostate may help.