Tight & Weak or Loose & Weak: Hypertonic vs. Hypotonic Pelvic Floor Muscles
January 04, 2021
For many people, knowledge of the pelvic floor starts and ends with the word “Kegels”. And while that’s definitely better than not knowing anything, there is a lot of value in having a bit deeper of an understanding of your pelvic region and what kinds of things can impact your pelvic health. After all, between its responsibilities around both sex and bladder control / incontinence, it can have a truly huge impact on your quality of life.
In this article, we want to tackle one of the most important nuances of pelvic floor dysfunction: the difference between a hypertonic pelvic floor and a hypotonic one. Hopefully that will help you get a better idea of how your body works and what it might mean if your body starts letting you down in certain ways (it CAN get better!).
(First, one note about nomenclature. There are a number of terms that people have used historically to talk about this topic. The main ones are "overactive", "high tone" and (historically) "hypertonic" to describe pelvic floor muscles that are too tight and "underactive", "low tone" and "hypotonic" to describe pelvic floor muscles that are too loose. As the pelvic floor health field evolves, the language evolves too, and some of the vocabulary is taking on more precise / specific meanings so that those terms may not really be interchangeable in a medical discussion. However, in this article (which is intended for the general public) we'll use multiple of the options to try to make it approachable for readers who may be familiar with different terminology and we'll leave an examination of the precise distinctions for another article.)
Before we dive into the details, a quick overview: the pelvic floor is a group of muscles, ligaments and connective tissue at the base of your pelvis. It plays a key role in continence and sexual function, among other areas. When your pelvic floor is too weak or loose, this is called hypotonic. In contrast, when your pelvic floor is too tight or tense and weak, this is called hypertonic.
What is hypotonic pelvic floor dysfunction?
As mentioned above, a hypotonic pelvic floor is basically too weak. It then struggles to fulfill its responsibilities in your body relating to your lower back, core muscles and pelvic organs (like the bowel, bladder and (at least for women) uterus).
There is not always an identifiable cause for a hypotonic pelvic floor (some people’s bodies just tend towards that direction) but there are also external factors that can contribute to a higher risk of a hypotonic pelvic floor, including pregnancy / childbirth and aging.
There are two main conditions that are caused by weak pelvic floor muscles: urinary incontinence (UI) and pelvic organ prolapse (POP). Furthermore, a weak pelvic floor can undermine your body’s healthy sexual function in areas such as arousal, sensation or orgasm.
Urinary incontinence boils down to a lack of control over when and how you pee. Depending on the type and severity, some individuals can experience minor leaks while others can leak larger volumes of urine, or more frequently.
If you suffer from UI, know that it is very common – approximately 33 million Americans suffer some type of urinary incontinence or bladder condition. And it is particularly a women’s health issue, with 75-80% of the sufferers being female.
There are 4 main types of urinary incontinence:
- Stress incontinence: this is the involuntary leakage of urine when increased pressure is put on the pelvic floor muscles by activities like coughing, sneezing, laughing, lifting, and exercise.
- Urge incontinence: this is a sudden and/or overwhelming urge to pee that is triggered when the bladder contracts even though it shouldn’t. It is also sometimes called overactive bladder (OAB).
- Overflow incontinence: this occurs when the bladder doesn’t empty fully/normally during urination. This can interfere with your ability to sense when your bladder is full, leading to leaking due to an overflow of urine as well as increasing your risk of urinary tract infections.
- Mixed incontinence: this is the name when both stress and urge incontinence are present; it is very common to have mixed incontinence as opposed to pure stress or urge incontinence.
Pelvic Organ Prolapse (POP)
Pelvic organ prolapse (POP) is a disorder in which the pelvic organs drop lower in the pelvis than they should be. This creates a bulge called a prolapse; it commonly occurs as a bulge in the vagina for women and can occur as a bulge in the rectum for both men and women. In both cases, the sufferer may have difficulty initiating urination or defecation.
Given that the common link across these types of hypotonic pelvic floor dysfunction is weakness in the muscles and other structures in the pelvic floor, exercise or strengthening (i.e. Kegels) is often a good place to start in terms of preventing or treating these problems.
What is hypertonic pelvic floor dysfunction?
In contrast to hypotonic pelvic floor muscles, overactive pelvic floor muscles are too tight or too tense (while still generally being weak). As with basically all your muscles, full range of motion is critical for your pelvic floor. They need to be able to contract or squeeze to maintain bladder control but they also need to remain flexible and relaxed much of the time to avoid pelvic and low back pain and allow use of the bladder and bowel movements when you actually want that (constipation is no fun, after all).
As with a hypotonic pelvic floor, sometimes this can occur without a direct cause, but there are external factors that can definitely contribute. These can include exercise that focuses on contracting the pelvic floor or creates pressure on the pelvic floor, like Pilates or cycling (although generally this requires a LOT of exercise).
Overall, hypertonic (or nonrelaxing pelvic floor disorders) are less well studied and well understood than hypotonic disorders -- in fact, it is not even well-established what the exact numbers are in terms of how many people have them. But there are a number of conditions that we do know can be related to overactive pelvic floor muscles, including dyspareunia, vaginismus, vulvodynia, chronic pelvic pain syndrome, and pudendal neuralgia (which we won't cover here).
Dyspareunia is the medical term for pain associated with sexual intercourse and can be caused by overactive pelvic floor muscles (although there are many other potential causes as well). Individuals suffering from this will often feel aching pain or burning during intercourse.
Vaginismus is a condition where the muscles of the vagina contract or spasm involuntarily whenever something is inserted (whether during sex, a medical exam, use of a tampon, or another situation). This contraction is usually accompanied by discomfort or even significant pain and is often related to overactivity of the pelvic floor.
Vulvodynia is a type of chronic pelvic pain focused on either the vestibule (or “entrance” of the vagina), clitoris, or the superficial tissues of the vulva. There are a number of factors that can correlate with vulvodynia, including nerve injury in the vulvar region or pelvic floor hypertonia (which is present in 80% of patients with vulvodynia), but it is imperfectly understood and the specific cause(s) are still an area of research.
The discomfort or pain mentioned above is the most common sign of vulvodynia, and that pain can take a variety of forms, including burning, itching or aching. It can be triggered by clothing contacting the vulvar region, physical activity, sexual activity, or even nothing at all.
Chronic Pelvic Pain Syndrome
Chronic pelvic pain syndrome is a type of prostatitis that generally causes perineal and genital pain in men. It frequently affects younger men (the median age in the US is 43) and is estimated to affect somewhere between 2-8% of men.
In addition to causing pain, it can also impact sexual function and urinary continence. It is also the leading cause of urinary tract issues for men younger than 50.
Often, chronic pelvic pain syndrome can be associated with pelvic floor muscle issues and in particular tight pelvic floor muscles; in this case the tension in those muscles and ligaments can irritate the surrounding nerves painfully.
High tone or low tone, whatever. How do I deal with it?
As with any medical issue, the first step should be to see a healthcare subject matter expert. A pelvic floor physical therapist, urologist, or your GP are all good places to start. They can check you out and provide individualized advice on next steps and treatment options, from physical therapy and lifestyle modifications to less conservative medical interventions if necessary.
With that said, there are some general tips and best practices to be aware of:
- Pelvic floor exercise is often a good tool to address a low tone pelvic floor. But it can be useless or even counterproductive for an overactive or high tone pelvic floor, so it’s very important to understand what is going on with your body specifically.
- There are ways to practice relaxing or down training your pelvic floor muscles if they are overactive. You can learn more here.
- Pelvic floor dysfunction is NOT inevitable, so don’t just accept it if you have it! Both low tone and high tone pelvic floors can generally be improved or fixed, often using nothing more than conservative therapies like exercise or lifestyle tweaks (no surgery required).