Written by Megan Jackson, Clinical Director & Specialist Pelvic Health Physiotherapist (MCSP, HCPC).
Acute pain, chronic pain — and the difference that matters
When we think of pain, most of us think of damage to our body.
A burn hurts because the skin is damaged.
Your bladder is painful because you have an infection.
Your calf muscle aches and pulls after you strained it.
It’s helpful because it reminds us to protect the area to allow it to heal.
But why does some pain start, seemingly out of nowhere, and why does pain continue even after any tissue damage or infection has healed?
We call new pain ‘acute’ pain – which is usually from an infection or injury. Pain that has been around for longer than 3 months is ‘chronic’ or ‘persistent’ pain. Chronic pain may have started with an injury or infection but there may be no obvious cause.
Persistent pain isn’t just acute pain that’s been going on a long time. It’s pain that is driven by entirely different mechanisms, which we’ll dig into in more detail.
Four people, four kinds of persistent pain
Let me share four common scenarios — and explore what might be going on in each one.
Anya
Anya went for her first cervical screening and found it very uncomfortable. She didn’t say anything at the time because she didn’t want to make a fuss. When she later needed follow-up treatment, that was painful too.
At her next screening appointment, she noticed her legs shaking. She felt frightened and tense, and the test was so painful she couldn’t complete it.
Over the following months, she began to notice discomfort when passing urine and pain with intercourse — things she had never experienced before.
Josh
Josh works in a high-pressure job and spends much of the day sitting. He’s had episodes of back pain over the years, but more recently he’s developed pain around the perineum along with some bladder and bowel discomfort. It’s worse when he’s sitting and sometimes flares after the gym.
He’s had scans and blood tests, all of which were reported as normal — which is reassuring medically, but confusing and frustrating for him. His symptoms have started to affect his erections, and that’s made him anxious about starting a new relationship. He’s stopped going to the gym and is avoiding social plans because he’s worried about making things worse.
Maria
Maria has recently gone through the menopause. Over the past eight months she’s had three confirmed urinary tract infections. Now, even though her most recent urine tests and a scan was negative, she feels as though she has one constantly.
She describes bladder discomfort and an internal burning sensation that fluctuates but never fully settles. She finds herself repeatedly wondering whether something serious has been missed.
Saskia
Saskia was diagnosed with endometriosis at 26 after 14 years of painful periods, pelvic pain, constipation, fatigue and bloating. She finally had laparoscopic surgery and was told the endometriosis had been successfully cleared.
Six months later, however, she doesn’t feel significantly better. Her pain is still there. She feels confused and disheartened — especially when she’s being told that “it’s all gone.”
What’s actually going on for each of them
Anya — painful cervical screening
What may have happened here?
When we have a painful or threatening experience, the brain’s threat detection system — including the amygdala — becomes activated. Its job is protection. It doesn’t distinguish particularly well between physical and emotional threat; it simply registers, “That wasn’t safe.”
When that system is activated, several things can happen:
- The pelvic floor muscles may increase in tone or guard reflexively.
- Nerve endings in the vulva and vagina can become more sensitive (peripheral sensitisation).
- The wider nervous system can become more reactive, especially if the experience was linked with anxiety or fear (central sensitisation).
This isn’t conscious or a choice. It’s protective physiology.
In the short term, muscle guarding and increased sensitivity are adaptive — the brain is essentially trying to prevent a repeat of what it experienced as a threat. But if this pattern is repeated, the system can become over-protective. The pelvic floor may stay tense even when it doesn’t need to. Sensory thresholds can lower, so normal touch or stretch feels painful and anxiety can further amplify sensitivity.
Over time, those protective responses can become the new pattern — which is when symptoms such as pain with penetration, urinary discomfort, or anticipatory fear around examinations can develop.
Importantly, this does not mean “it’s in her head.” It means her nervous system learned from experience.
Josh — pelvic pain and ED
What might be happening?
Firstly, normal scans do not rule out pain. Many pelvic pain conditions are functional rather than structural — meaning the tissues are intact, but the way the muscles and nerves are behaving has changed.
Josh may have some stiffness through his lower back and hips from prolonged sitting. The pelvic floor works closely with these areas. If movement patterns are restricted, the pelvic floor can lose some of its natural mobility.
On top of that, stress plays a powerful role. When we’re under ongoing stress, we often unconsciously tense the abdomen and pelvic floor. Over time, that low-grade guarding can become habitual. Muscles that are constantly braced don’t move well, don’t relax well, and can become tender and irritable.
Increased muscle tone in the pelvic floor can:
- Create perineal aching or pressure
- Irritate nearby nerves, increasing sensitivity
- Disrupt normal bladder and bowel function
- Affect erectile function, because erections rely on a balance of relaxation, blood flow and nervous system regulation
None of this would necessarily show up on a scan.
Finally, worry about symptoms — especially around sexual function — can amplify the problem. Anxiety increases sympathetic (“fight or flight”) activity, which is not the state the body needs for healthy sexual function. Avoiding activity and social contact can also increase stress load and reduce confidence in the body.
Maria — repeated UTIs
What could be happening?
During and after menopause, oestrogen levels fall. Oestrogen plays an important role in maintaining the health and thickness of the tissues in the vagina, urethra and bladder. When levels decline, those tissues can become thinner, drier and more sensitive. The protective bacterial balance changes, and this can increase susceptibility to urinary tract infections.
So the initial infections are entirely plausible in the context of hormonal change.
However, after several infections, the nervous system can become more protective. Repeated inflammation in the bladder can lower the threshold at which nerve endings fire, meaning normal sensations — bladder filling, urine passing, even clothing pressure — may feel uncomfortable or burning.
Importantly, once this sensitisation has developed, symptoms can persist even when there is no active infection. That’s why urine tests can be negative but the discomfort is very real.
Layered on top of that is understandable worry. When someone has had repeated infections, it’s natural to scan for symptoms and fear recurrence. Ongoing vigilance increases stress-system activity, which can further amplify bladder sensitivity.
This doesn’t mean the symptoms are “in her head.” It means the bladder and its nerve supply have become more reactive following hormonal change and repeated inflammation.
Saskia — endometriosis surgery and what came after
Saskia doesn’t feel she has made a good recovery from her surgery. This is, unfortunately, not uncommon.
Endometriosis can absolutely drive pain through inflammatory and mechanical mechanisms. But when pain has been present for many years, the nervous system can become sensitised. Repeated monthly flares, ongoing inflammation and years of bracing against pain can lead to both peripheral sensitisation (more sensitive local nerve endings) and central sensitisation (increased responsiveness within the spinal cord and brain).
Surgery removes visible endometriotic lesions, but it does not automatically reset a sensitised nervous system.
In addition, surgery itself is a physical stressor. Even when performed skilfully, it can temporarily increase inflammation, alter tissue mobility and reduce strength and conditioning. Post-operative guarding, reduced activity and fear of triggering symptoms can further affect movement patterns and pelvic floor behaviour.
So Saskia’s ongoing symptoms do not necessarily mean the surgery “failed.” They may reflect a nervous system that has been on high alert for many years and now needs targeted rehabilitation.
The common thread: a nervous system on high alert
What unites Anya, Josh, Maria and Saskia is one underlying mechanism: a nervous system that has become over-protective¹. It might have started with a painful procedure, work stress, repeated infections or years of chronic pain — but the end result is similar. The brain and nervous system have lowered the threshold at which they sound the alarm. The pelvic floor stays guarded. Normal sensations start to feel uncomfortable. This isn’t damage, and it isn’t imagined — it’s protective physiology working too hard, for too long.
The good news is that what can be learned can also be unlearned. Targeted physiotherapy, graded movement, breathing and nervous-system regulation, and education about what your body is actually doing can gradually coax the system back toward calm.
What treatment actually looks like
Persistent pain usually means the system has become over-protective, not that you are broken or that damage is ongoing. The key is approaching it properly. That often means looking beyond a scan, surgery or a prescription and working on the whole picture — movement, muscle behaviour, hormones, stress, sleep, confidence and understanding what’s actually driving the pain. Some people will need support from a team of health professionals, from physiotherapists, psychologists, pain specialists and dieticians.
At Pelvix, persistent pelvic pain is one of the things we see most. Our approach combines hands-on therapy, graded movement, breathing and nervous-system regulation, and education that helps you understand what your body is doing — and why. We work with a specialist pelvic health physiotherapist for women, a specialist pelvic health physiotherapist for men, and alongside the wider team where joined-up care is needed.
Recovery isn’t a quick fix, but it is absolutely possible. And with the right support, people do get better.
When to see your GP first
A caveat: new symptoms always need to be checked out by an appropriately qualified professional. The mechanisms described in this post apply to persistent pain — pain that’s been around for more than three months with thorough investigation behind it. If your symptoms are new, if they’re getting worse, or if you have any “red flag” symptoms — unexplained bleeding, unexplained weight loss, fever, sudden changes in bowel or bladder function — please see your GP before anything else.
Related conditions: Pelvic Pain | Endometriosis | Erectile Dysfunction | Overactive Bladder | Constipation
Related services: Women’s Pelvic Health | Men’s Pelvic Health
Related reading: When Your Bladder Runs the Show (And How to Take Back Control)
References
1. Woolf, C.J. (2010). Central sensitization: Implications for the diagnosis and treatment of pain. Pain, 152, pp. S2–S15. doi: 10.1016/j.pain.2010.09.030
Reviewed by Megan Jackson, Clinical Director & Specialist Pelvic Health Physiotherapist (MCSP, HCPC).
Last reviewed: 4 June 2026.