How Spinal Cord Injuries Cause Bladder Problems

This post has been medically reviewed by Susie Gronski, DPT, PRPC, WCS.

Around 80% of people who have experienced a spinal cord injury (SCI) experience a loss of bladder control, a condition known as neurogenic bladder. Adjusting to life with this condition can be challenging at times, but there are ways to maintain the health of your bladder and pelvic floor.

This post will teach you...

  • What normal bladder function looks like.
  • How SCI affects your bladder.
  • What continence care products you can use for your condition.
  • How to get products through insurance.
  • Plus, incontinence care tips!

Typical Bladder Function

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Your bladder reflexes are similar to the reflexes in your knee (that knee-jerk reaction your healthcare provider tests with a little rubber hammer). Here’s how they function.

  1. Your bladder fills with urine.
  2. The bladder’s sensory nerves (sacral spinal nerves: S1, S2, S3, S4 ) send signals to the spinal cord.
  3. The spinal cord responds, sending signals to the bladder to contract.

These signals are sent on a two-way superhighway that communicates with your entire body. The same sensory nerves that communicate with your bladder also communicate with your pelvic floor muscles, aiding in your ability to decide when you want to pee and when you don’t want to pee your pants.

Like all reflexes, your brain plays an integral part in the micturition (the “peeing”) process. If we didn’t have our brain’s ability to put the brakes on this bladder reflex, we would find ourselves urinating every 10 minutes (yikes!). Our brain has the power to dampen this reflex so that we can hold our urine for at least 2-3 hours, which is a standard time in between voids.

When the bladder is full (approximately 1.5 cups to 2.5 cups), the messages making their way from your bladder to your spinal cord and then to your brain get louder and louder. Once these messages succeed in grabbing your brain’s attention, you become consciously aware that your bladder is full and you need to go.

Bladder flow chartBladder flow chart

Once you’ve decided to empty your bladder, your brain releases the brakes on the bladder reflex, the pelvic muscles (urinary sphincter muscles) relax, and your bladder muscle gets the “OK” to contract to let go and let flow.

Spinal Cord Injuries & the Bladder

We’ll need to learn some basic anatomy to understand how the spinal cord and brain impact normal bladder function.

Signals to and from the spinal cord travel up and down a neural superhighway to your brain. The brain also sends signals to your spinal cord using this same pathway.

The different spinal cord levels that make up your neural pathway are involved in different bladder functions:

T10 - L2: These spinal cord levels and their accompanying peripheral nerves are involved in:

  • Bladder muscle relaxation.

  • Urinary sphincter contraction.

  • Storage of urine.

S1 - S4: These spinal cord levels and their accompanying peripheral nerves are responsible for:

  • Sensation
  • Voluntary motor control (muscle activation).
  • Voluntary motor control of pelvic floor muscles such as the urinary sphincter relaxation, bladder muscle contraction, and elimination of urine. 
Spinal cords group twoSpinal cords group two

What Happens to the Bladder After an SCI?

Bladder function depends on the level of the spinal cord injury and whether it’s complete or incomplete. To keep it simple, we’ll focus on complete spinal cord injury presentations, which occur when the nerves below the injury no longer communicate with the brain.

Injuries Above the Sacral Nerve Level

Spinal cordsSpinal cords

With these types of injuries, the bladder reflex does come back, but because the brain cannot communicate with the bladder and do its part, the bladder reflex takes over and runs the show. This can lead to:

  • Involuntary loss of urine.
  • Difficulty storing urine.

Over time, the bladder muscle contractions or spasms might intensify because the ring leader- the brain- cannot send signals to stop the bladder’s reflex and end the show. This makes it hard for your bladder to fill up all the way because it’s contracting faster and more often, stopping your bladder from stretching. When this happens, the bladder walls thicken, making the bladder work harder than it needs to, causing the muscles to become stiff.

When the bladder muscle gets too stiff, it’s no longer easy for the bladder to hold urine and empty it efficiently, resulting in a high-pressure situation in the bladder. This is due to the inability to accommodate any amount of urine, even a tiny amount.

Your body always looks for the path of least resistance, which means that you’ll likely experience bladder leakage, or the urine will back up into the kidneys to accommodate this high-pressure situation.

If the sphincter muscles are spastic, it is difficult for urine to leave your bladder when the bladder muscle contracts. It also makes fully emptying your bladder challenging. This can lead to frequent urinary tract infections (UTIs), kidney hydronephrosis (urine backflow to the kidneys), and incontinence.

Typically, the bladder muscle and urinary sphincter muscles around the bladder coordinate to help with the bladder filling and emptying. Still, with an SCI, these muscles work out of sync. 

Injuries at the Sacral Nerve Level

When these injuries occur, your bladder function is impacted slightly differently, where the bladder muscle becomes flaccid or weak. The bladder reflex is impacted and results in diminished:

  • Bladder sensation.
  • Urges to urinate.
  • Ability to contract.

This leads to a bladder that can hold a lot of urine without you being aware of how full your bladder actually is. When you’re ready to empty, it's challenging for your bladder muscle to perform its job.

This may result in bladder problems, such as urinary retention and forceful pushing using your abdominals to help squeeze your pee out.

Over time, your bladder, prostate, rectum, uterus, and pelvic ligaments become strained and stressed. Sometimes, pelvic organ prolapses can occur if there’s too much strain on the organs.

People with SCIs at the level of the sacral spinal nerves commonly experience stress urinary incontinence, which involves leaking when coughing, laughing, sneezing, or other exertional activities.

Managing Incontinence & SCI

Every person’s incontinence situation is unique and should be supported individually to determine the best treatment approach for you. 

We recommend a few products for people with SCI and incontinence symptoms.

  • Intermittent catheters: With these short-term catheters, you can empty your bladder throughout the day. Intermittent catheters are typically used 4 to 6 times a day.
  • Adult or pediatric briefs: Briefs are excellent for bladder control because they are absorbent and open easily with tabs on the sides. This allows you to change your brief easily if you use a wheelchair or have less mobility. Briefs are best for those with heavier leakage.
  • Adult or pediatric protective underwear: Designed to look and feel like real underwear for both males and females, protective underwear (pull-ups) are absorbent and discreet. You should use protective underwear if you have moderate leakage.

Getting Products Through Insurance

Continence care products, such as intermittent catheters, adult briefs, and protective underwear can successfully manage incontinence if you have SCI. The products that are best suited for you will be based on your level of mobility and your specific injury, and you may be eligible to get them covered through your Medicaid or Medicare plan with Aeroflow Urology!

To see if you qualify for coverage, fill out our 2-step Eligibility Form. Once you qualify, we’ll reach out to your healthcare provider for a prescription on your behalf, and if you’d like to get your products even quicker, you can contact your provider’s office and let them know we’ll be requesting a prescription!

We’ll then ship your order in discreet boxes right to your doorstep for free. You can also refill your supplies monthly with our easy-to-use refill process.


Parittotokkaporn, S., et al. (2021). Transcutaneous Electrical Stimulation for Neurogenic Bladder Dysfunction Following Spinal Cord Injury: Meta-Analysis of Randomized Controlled Trials, Journal of the International Neuromodulation Society, 24(7), 1237-1246. DOI: 10.1111/ner.13459 

The Neurogenic Bladder Research Group.(2015, December 31). Neurogenic bladder. Patient Information library. Retrieved from

Al Taweel, W., & Seyam, R. (2015). Neurogenic bladder in spinal cord injury patients. Research and Reports in Urology, 85.

Dr. Susie Gronski, PT, DPT

Specializing in men’s pelvic and sexual health, Susie Gronski, PT, DPT is a Medical Advisor and Writer for Aeroflow Urology and a licensed doctor of physical therapy, certified pelvic rehabilitation practitioner, Michigan-trained sex counselor and educator, international teacher, and author of "Pelvic Pain The Ultimate Cock Block: A No-bullshit Guide for Men Navigating Through Pelvic Pain." Learn more at

Edited by Marlee Septak


Information provided on the Aeroflow Urology website is not intended as a substitute for medical advice or care from a healthcare professional. Aeroflow recommends consulting your healthcare provider if you are experiencing medical issues relating to incontinence.