Your Body

Endometriosis: when it was never “just a bad period”

Endometriosis is a condition where tissue similar to the lining of the womb grows in places it should not: on the ovaries, the fallopian tubes, the ligaments holding the womb, the outside of the bowel or bladder, the lining of the pelvis. That tissue still responds to your monthly hormones, so it thickens and bleeds like a period would, but it has nowhere to go. The result is inflammation, internal scarring and adhesions, bands of scar tissue that can stick organs to each other. It affects around one in ten women and people with a womb of reproductive age, which makes it about as common as diabetes, and in the UK it still takes an average of around eight years to be diagnosed.

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Sound like you?

Endometriosis pain is often described as being told, repeatedly, that something normal is happening to you.

🛏️Period pain that stops you working, studying or standing up, not pain that a paracetamol sorts out.

🗓️Pain that has started arriving outside your period too, not just during it.

💔Sex hurts, sometimes during and sometimes as a deep ache for a day afterwards.

😫A tiredness that has nothing to do with how much you slept.

💜If you have been told to expect this much pain, you were told wrong. Severe period pain is common, but it is not normal, and it deserves investigating.

What it actually is, in plain terms

Cells similar to womb lining, growing outside the womb. Each month they respond to oestrogen, build up and bleed. Because the blood cannot leave the body, it irritates whatever is nearby. Over years that inflammation forms scar tissue and adhesions, which is why the pain can become constant rather than monthly, and why it can pull on the bowel or bladder. Endometriosis is not an infection, it is not caused by anything you did, and it is not a sign you are run down.

The symptoms that are easy to miss

Severe period pain is the famous one, but the fuller list is: pelvic pain between periods, pain during or after sex, pain when opening your bowels or passing urine, heavy or clotted bleeding, bleeding from the bowel, bloating that comes and goes dramatically (often called “endo belly”), exhaustion, and difficulty getting pregnant. Pain that flares cyclically in an odd place, a shoulder, the lower back, one leg, can also be endometriosis, because the tissue can sit almost anywhere in the pelvis.

Why diagnosis takes so long

Three reasons, and none of them are your fault. Period pain has been normalised for generations, so symptoms get minimised by patients and clinicians alike. Ultrasound and MRI often look completely clear even in significant disease, so a normal scan does not rule it out. And the definitive test is a laparoscopy, keyhole surgery under general anaesthetic, so there is a real threshold to cross before anyone looks. Knowing this helps you push: a clear scan is not an answer.

What treatment actually looks like

There is no cure yet, but there is a lot of treatment. Pain relief, usually anti-inflammatories such as ibuprofen or naproxen taken before pain peaks rather than after. Hormonal treatment to quiet the cycle: the combined pill taken back-to-back, progestogen-only options, the hormonal coil, or GnRH analogues for more severe cases. Surgery to excise (cut out) rather than just burn the tissue, ideally at a specialist centre. And pelvic health physiotherapy, which is genuinely underrated for the muscle tension that builds up around chronic pelvic pain.

Pain that has been dismissed is still real. Your experience was always evidence, even when nobody wrote it down.

Getting taken seriously, and living with it day to day

The practical part: how to build a case a GP can act on, and what helps in the meantime.

Keep a pain diary for three cycles

Date, pain score out of ten, where it hurt, what you could not do that day, what you took and whether it helped. Three cycles of this is far harder to wave away than “my periods are bad”, and it is exactly the evidence NICE guidance expects. Note anything cyclical and unusual too, bowel pain, bladder pain, shoulder pain.

Ask for the specific things

Useful sentences: “I would like to be referred to gynaecology to investigate endometriosis.” “I understand a normal ultrasound does not rule it out, can we still refer?” “Could I be referred to a BSGE-accredited endometriosis centre?” If you are dismissed, you are allowed to book with a different GP at the same practice. That is not rude, it is normal.

Treat the pain properly, not stoically

Take anti-inflammatories at the first sign rather than waiting to see how bad it gets, they work by blocking the chemicals that drive the cramping, so timing matters. Heat genuinely helps: a hot water bottle, a heat patch you can wear under clothes, a bath. A TENS machine is cheap, drug-free and works well for a lot of people. None of this is a substitute for investigation, but you do not have to suffer while you wait.

Look after the parts that get overlooked

Chronic pelvic pain tightens the pelvic floor, which then adds its own pain, so a referral to pelvic health physio is worth asking for. Heavy bleeding drains iron, so ask for a ferritin check, not just a standard full blood count. And the mental load of years of pain and being disbelieved is real: therapy for chronic illness is a legitimate thing to want, not an admission that the pain is psychological.

Fertility, if it is on your mind

Endometriosis can affect fertility, but plenty of people with it conceive without help. If you are trying and it is not happening, the guidance is to seek advice sooner rather than waiting the usual twelve months, because having a diagnosis changes the options available to you. If you are not trying, you do not owe anyone a conversation about it.

🧰Your endometriosis tool kit

Endometriosis UK The national charity. Free helpline on 0808 808 2227, local support groups, and a symptom diary you can print and take to an appointment. Their information is reliable and written for patients, not clinicians.

The NHS endometriosis pages Plain, accurate, and useful to read before an appointment so you know the terminology being used at you.

BSGE accredited centres The British Society for Gynaecological Endoscopy lists specialist endometriosis centres in the UK. You can ask to be referred to one by name, which is often the difference between burning the tissue and properly excising it.

Practical pain kit A wearable heat patch, a TENS machine, loose clothing for bloating days, and anti-inflammatories taken early. Small, unglamorous, and they make ordinary days possible.

✨Try this: build your three-cycle case

The single most effective thing you can do while waiting for anyone to take this seriously:

Start a note on your phone today. Each day you have pain: the date, a score out of ten, and one line on what it stopped you doing.
Log what you took and whether it worked. “Ibuprofen, no difference” is clinically meaningful.
After three cycles, write your top three problems as one sentence each. Take the note with you.
Open the appointment with the impact, not the pain: “I have missed four days of work in three months.” Impact is what moves referrals.

Going deeper: what endometriosis is and why it is missed

If you have been told your pain is normal for years, understanding the mechanism matters twice over: it explains the symptoms, and it explains the delay.

Tissue in the wrong place, behaving as it was built to

The lining of the uterus is designed to thicken and then shed each month. In endometriosis, tissue similar to that lining grows outside the uterus, most often on the ovaries, the fallopian tubes, the ligaments supporting the uterus, the bowel or bladder surfaces, or the lining of the pelvis. It responds to the same hormonal signals as the lining inside, so it thickens and bleeds in the same monthly rhythm.

The difference is that it has nowhere to go. Blood and tissue inside the uterus leave through the cervix; blood outside it cannot. What follows is inflammation, and over time the body responds to repeated inflammation by laying down scar tissue and adhesions, sticky bands that can bind organs to one another. That is why the pain is not confined to bleeding days, why it can involve the bowel and bladder, and why it often becomes more complicated over years rather than staying still.

Deposits are often small. Severity of pain and extent of disease are famously poorly correlated.

Why diagnosis takes so long, and why that is not your fault

Diagnostic delay in endometriosis is measured in years, and there are structural reasons for it rather than individual ones. Period pain is culturally expected, so both patients and clinicians can normalise severe pain. Symptoms overlap heavily with irritable bowel syndrome, bladder conditions and pelvic inflammatory disease. Ultrasound scans frequently look completely normal, because superficial deposits are often too small to see, so a clear scan does not rule anything out.

Laparoscopy, keyhole surgery to look directly inside the pelvis, has historically been the definitive diagnosis, and the wait for it is long. More recently, UK guidance has encouraged clinicians not to wait for surgical confirmation before starting treatment where the symptom pattern fits, which matters practically: you can ask about managing suspected endometriosis now rather than being left with nothing until a scan or surgery happens. Knowing that a normal scan is not an answer is one of the most useful things you can take into an appointment.

The words worth knowing

Adhesions. Bands of scar tissue that can stick organs together. They help explain pain that is not limited to bleeding days, and pain on movement, sex or opening the bowels.

Endometrioma. A cyst of old blood on an ovary, sometimes called a chocolate cyst. These are visible on scans, which is part of why some people are diagnosed quickly and others are not.

Laparoscopy. Keyhole surgery through small incisions, allowing deposits to be seen and often treated in the same operation.

Dyspareunia. Pain during or after sex, particularly deep pain. Common in endometriosis, frequently not mentioned in appointments, and important to say out loud because it points towards specific sites.

Central sensitisation. When a nervous system exposed to long-term pain becomes more efficient at producing it, so pain can persist or spread even after deposits are treated. It is a real mechanism, not pain being imagined, and it is why pain management alongside surgery matters.

Three things that are commonly got wrong

The beliefA normal ultrasound means I do not have endometriosis.

Closer to the truthScans can be entirely normal in significant endometriosis, because most deposits are too small or too flat to show. A normal scan rules out some things, such as large cysts and fibroids. It does not rule this out, and it is reasonable to say so.

The beliefPregnancy or a hysterectomy cures it.

Closer to the truthNeither is a cure. Some people experience a temporary easing during pregnancy and some do not. Because deposits sit outside the uterus, removing the uterus does not necessarily remove the disease. Both are sometimes offered as reassurance, and both are more complicated than that.

The beliefSevere pain means severe disease, and mild disease means I am overreacting.

Closer to the truthThe relationship between how much tissue is present and how much pain it causes is weak in both directions. Extensive deposits can cause little pain, and a small amount in a sensitive location can be debilitating. The staging system describes the disease, not your experience of it.

Making the system work for you

Documentation is the most powerful tool you have, because it converts a story into a pattern. Keep two or three cycles of notes covering pain scores, painkillers taken, days where you could not work or attend, bleeding, bowel and bladder symptoms, and pain with sex. Written evidence of days lost is markedly harder to dismiss than an account given from memory in a ten minute appointment.

Ask for specifics rather than reassurance. Useful questions include whether your symptom pattern is consistent with endometriosis, what can be started now while you wait, whether referral to a gynaecologist is appropriate, and whether a specialist endometriosis centre would be relevant if your symptoms involve bowel or bladder. If you feel dismissed, you are entitled to ask for a second opinion, and asking for one is a normal part of healthcare rather than a complaint. Endometriosis UK maintains helplines and support groups, and hearing from people who navigated the same delay is genuinely useful when the process is grinding.

Why this matters

Being in pain for years while being told it is normal does something to you beyond the pain itself. You start doubting your own perception, downplaying symptoms before anyone else can, and treating your own body as an unreliable narrator. Naming the condition undoes some of that. It will not remove the pain, but it replaces “I think I am being dramatic” with “this is a recognised inflammatory disease and I am allowed to be treated for it”. That shift matters, and you are not starting from scratch, there is a whole community of people who have been exactly here.

This is general information, not a diagnosis. Only a specialist can diagnose endometriosis, usually with a laparoscopy. Please see a GP if period pain is affecting your daily life. Seek urgent medical help for sudden, severe pelvic pain, heavy bleeding that soaks a pad an hour, fainting, or pain with a fever, as these can point to something that needs treating immediately.

Understand it

Endometriosis happens when tissue similar to the womb lining grows elsewhere. Pain severity does not reliably show how extensive it is, and a normal scan does not always rule it out. Symptoms can include pelvic pain, painful sex, bowel or bladder pain, fatigue and fertility difficulty.

You might also notice:

Period pain that stops you working, studying or standing up, not pain that a paracetamol sorts out.
Pain that has started arriving outside your period too, not just during it.
Sex hurts, sometimes during and sometimes as a deep ache for a day afterwards.
A tiredness that has nothing to do with how much you slept.
A gentle place to start: What it actually is, in plain terms.
Another thing worth trying: The symptoms that are easy to miss.

In real life

Cancelling plans every month, needing recovery time after sex or planning journeys around toilets are functional impacts, not just “bad periods.” Recording them helps show what pain is costing you.

Other ways this can show up:

Sex hurts, sometimes during and sometimes as a deep ache for a day afterwards.
A tiredness that has nothing to do with how much you slept.
Period pain that stops you working, studying or standing up, not pain that a paracetamol sorts out.
Pain that has started arriving outside your period too, not just during it.
One small thing to try: Why diagnosis takes so long.
You might also try: What treatment actually looks like.

Trusted next step: NHS endometriosis guidance