Understanding Bladder Control and Urinary Function Basics

There are many myths and misconceptions around bladder and pelvic health.  And, because it’s often considered “taboo” or embarrassing to talk about, many women don’t share their experiences or concerns with one another – or, unfortunately, with their healthcare providers.  Despite their silence, nearly 1 in 3 U.S. women suffer from bladder control issues (i.e., incontinence). This suffering can cause negative impacts across all aspects of a woman’s life – social, physical, mental and sexual health – leading to a domino effect that can be easily avoided with the bravery to speak up. But, in order to gain your voice, it’s helpful to better understand what’s “normal” regarding how your bladder should work, so let’s start at the beginning…

How Your Bladder Works

Your bladder is a muscle in your pelvis that stores urine and is intended to control how your body releases urine from the body. When working properly, urine eventually exits your bladder under your own control, allowing it to travel into your urethra, which then carries urine out of the body.

While it sounds simple, the proper function of your bladder is much more complicated to achieve than you may expect, and involves the cooperation of several body parts: the brain, nerves at the level of the bladder and spinal cord, the bladder muscle, urethra, and pelvic muscles.  These parts all work together to ensure women can maintain bladder control – meaning no leakage and a normal frequency of urination (i.e., not causing you to urinate too many times throughout the day). If there is an issue with any of these parts, your bladder may not function correctly.

Women often believe bladder relaxation is what causes urinary leakage, but the exact opposite is true. Muscle contraction (remember: your bladder is a muscle!) is what leads to urine exiting your body. Therefore, your bladder should actually be relaxed 95% of the time, with contraction only occurring about 5% of the time, when you intentionally urinate.

Now that you understand the impact of bladder relaxation and contraction, it’s clear how an “overactive” bladder actually references overactivity, or frequent contraction, of the bladder, which leads to the need to urinate frequently and can cause leakage on the way to the bathroom.  Overactive bladder is a common issue that occurs in nearly 43% of U.S. women, but the bladder alone is not to blame. Another important part of your body controls your bladder. That part is your brain.

The Role of Your Brain in Bladder Control

Your brain has ultimate control over your bladder. The bladder contains nerves that sense when it is filling with urine and subsequently sends a signal to the brain to let you know it is partially full, full, or really full—giving you that “9-1-1-you-better-find-a-bathroom-now” feeling.

It is your brain and nervous system that allow you to have control of your bladder, including the entire process of telling your bladder to store urine (relax) or empty urine (contract).  This is good news for women because it indeed often possible to retrain your bladder, putting you back in control. As a certified continence care nurse practitioner, I often share with my patients the mantra: “brain over bladder; not bladder over brain.” It’s empowering to know you can regain control over your bladder issues.

However, because other body parts also play a role in proper bladder function, there are instances in which other areas must be addressed in order for your brain to properly maintain control. To understand these situations, let’s look closer at how urination works.

A Closer Look at Urination

The bladder muscle should hold 1½ to 2 glasses of fluid (i.e., the equivalent to 300cc-600cc).  It is normal to urinate six to seven times per day and to sleep through the night if you are under the age of 60.  After the age of 60, it may be normal to urinate up to two times a night.  It is normal to drink 48-64 oz. of fluid. If you choose to drink coffee, tea, or soda as your primary beverage, you may notice that you go to the bathroom with more urgency and may go more often. That is because these fluids are known to be bladder irritants.

The Urethra

Eventually, the urine exits the body through the urethra, which is the small tube that extends from the bladder to the outside of the body (think of it as the passage way for urine to exit).  The urethra contains sphincters, which are structures like doors that keep the passage way closed.

The urethra is supported by the muscles and ligaments in the pelvic floor.  The urethra should be stable, meaning staying in the same position whether you are sitting, moving, running, jumping, coughing, sneezing.  If the muscles or ligaments no longer support the urethra—say, due to damage during child birth, chronic cough, or straining from chronic constipation—the urethra can wiggle. The medical term for this is “urethral hypermobility,” and this movement of the urethra can happen whenever there is an increase in pressure in the belly, such as with cough, sneeze, run, jump, laugh. As a result, urine leakage will occur.

Sample Urination Process

Let’s examine how a normal urine storage and emptying process may play out, step by step:

1. Urine is made in the kidneys and goes to the bladder.
2. The bladder stores the urine.
3. When the bladder gets about 1/3 full, the nerves in the bladder sense the filling. The nerves then send a signal from the bladder through the spine to the brain and tell you that you need to urinate.
4. But wait! You are driving in the car and can’t go to the restroom, so your brain sends a signal to the bladder to relax. At the same time, the nerves send a signal to the urethra and pelvic muscle to tighten and contract.  The urge goes away.
5. A little while later, you get a normal urge to urinate, but you are in a meeting and you can’t go. The same process as before happens, your bladder relaxes, urethral sphincters tighten, pelvic muscle tightens, and the urge should go away.
6. Eventually your bladder will fill to capacity, the nerves sending a signal that you must go—a 9-1-1 sense of urgency. The brain should control all the parts until you get to the bathroom.  Once in the bathroom and on the toilet, the brain stops causing the bladder to relax, at which point urination will occur.
7. The urethral sphincters or doors relax, the pelvic muscle will relax, the bladder contracts or squeezes, and urination begins.

If all parts are working correctly, you should not experience leakage of urine. Additionally, is NOT normal to have a small amount of leakage when you cough, sneeze, exercise, yell, or laugh.  Is it common?  Yes, it is.  Thirty percent of all women under the age of 65 have this type of urinary leakage.  It is called “stress incontinence.”  Now that you are more familiar with bladder basics, we encourage you to monitor your body and don’t be afraid to speak up if you experience bladder issues. Your Axia Women’s Health provider can connect you with a specialist to get you on a path toward recovery. It’s time to stop suffering!