What Are The Causes Of Overactive Bladder?

Overactive bladder is a condition that affects millions of people, yet many of us are unsure about what causes an overactive bladder. Overactive bladder leaves you looking for the closest bathroom which can be especially inconvenient when you are in a new and/or public place. But there is hope!!! In fact, the rate of success with conservative management is is 85-90%!!!

In this blog, we will explore:

• What is overactive bladder?
• Some key misconceptions
• Different types of overactive bladder
• The causes of overactive bladder
• How to manage your symptoms

What is Overactive Bladder?

As stated above, overactive bladder (OAB) affects millions of people and is characterized by an increased sense of urgency. There are two main types of bladder urgency, each caused by different mechanisms:

• Increased Bladder Sensation: Urgency with the feeling that the bladder is full.
• Sudden Urgency: Urgency without the sensation of fullness.

There are often misconceptions about the causes of OAB. It is important to be aware of these misconceptions, and the true causes of overactive bladder, so you can effectively manage your symptoms. If you have any questions or are experiencing urgency reach out to a pelvic floor physical therapist to get evaluated. At Optimize Pelvic Health, our pelvic floor specialists are experienced in treating the true causes, and symptoms of overactive bladder.

Contrary to Popular Belief: The True Cause of Overactive Bladder (OAB)

Overactive Bladder (OAB) is often misunderstood. While many medical professionals point to detrusor overactivity—overactivity of the bladder muscle—recent research shows that OAB is more about sensory dysfunction than detrusor muscle issues. To effectively manage OAB and achieve lasting symptom relief, it’s crucial to understand its true causes.

The Two Types of Overactive Bladder

Type 1: Increased Bladder Sensation (The Bladder Feels Full)

This type of urgency happens when the bladder feels very full due to sensory triggers. Normally, the epithelium, the lining of the bladder, stretches as the bladder fills. The stretching causes the bladder tissue to release an enzyme, ATP (adenosine triphosphate), which binds to nerves signaling the brain to void. However, abnormal tension in the bladder lining causes an excessive release of ATP, triggering urgency even when the bladder isn’t full.

Key Causes of Increased Bladder Sensation (Type 1)

Extrinsic Bladder Pressure When pressure from external factors limits the bladder’s ability to expand, the epithelium releases excessive ATP into the sensory fibers, causing urgency. This can be caused by physical restrictions around the bladder.

Causes:

1. Low Estrogen Levels Estrogen is critical in allowing the epithelium to stretch properly. When estrogen decreases, as it does during menopause or postpartum, the bladder lining tightens and releases ATP abnormally, leading to increased urgency.
   • Causes:
     • Menopause
     • Postpartum hormonal changes
   • Treatment:
     • Topical estrogen therapy to restore elasticity in the epithelium.
2. Fast Bladder Filling Rapid bladder filling stretches the epithelium quickly, releasing more ATP and triggering urgency. The bladder normally fills at about 3 ounces per hour. Drinking more than 6 ounces of water per hour can quadruple the likelihood of urgency.
   • Causes:
     • Overhydration
   • Treatment:
     • Space out fluid intake to avoid rapid bladder filling.

Type 2: Sudden Urgency (The Bladder Doesn’t Feel Full)

Sudden urgency occurs without the sensation of a full bladder. This type of urgency is often linked to urethral issues rather than bladder fullness.

Key Causes of Sudden Urgency

1. Urethral Instability During normal urination, urine in the urethra signals the bladder muscle (detrusor) to contract, helping continue the urine stream. However, weakness in the urethra—often due to pudendal nerve compression—can cause the urethra to send premature signals, triggering sudden urgency.Treatment:
   • Deep pelvic floor muscle releases and stretches
   • Outer layer pelvic floor muscle training to improve strength.
2. Bladder Neck Funneling Increased pressure at the bladder neck combined with urethral weakness and loss of fascial support can allow urine to enter the upper urethra prematurely. This is the cause of “stand-up urgency,” where the urge to void hits suddenly when standing.Treatment:
   • Pessary (a device for bladder support) can help.
   • Pelvic floor muscle training (PFMT) targeting both deep and outer layers.
3. Abnormal Cortisol Triggering of Micturition Our brains create associations between activities and voiding. For instance, if you always go to the bathroom after coming home, your brain may link having the key in the door to needing to void, causing sudden urgency. This is commonly referred to as “key-in-door urgency.”Treatment:
   • Disassociate voiding from specific activities. Break the connection between certain actions and the need to urinate by consciously delaying the urge during those activities.

Final Thoughts: Understanding and Managing OAB

Overactive bladder, especially in women, is often rooted in sensory dysfunction rather than just muscle overactivity. Whether you’re experiencing urgency due to increased bladder sensation or sudden urgency without fullness, addressing the underlying causes is key to effective treatment. By understanding the mechanisms behind OAB, you can work with your healthcare provider to develop a treatment plan that offers long-lasting relief.

Takeaways:

• Minimize constipation and reduce external pressure on the bladder.
• Consider topical estrogen if low estrogen levels are contributing to OAB.
• Avoid overhydration by spacing out fluid intake.
• Address urethral instability and bladder neck issues through pelvic floor therapy and pessary use.
• Break behavioral associations by disassociating certain actions from voiding.

This holistic approach targets the root causes of OAB and promotes long-term symptom management.