Stages of Endometriosis: Symptoms, Diagnosis, and What Comes Next

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Endometriosis is a chronic condition that affects millions of women around the world. In Malaysia, that number is around 350,000 women. While the symptoms can vary widely— from mild cramps to debilitating pain— understanding how the disease progresses is a key step toward managing it effectively.

If you’ve been diagnosed with endometriosis, or think you might have it, you’ve probably heard terms like “Stage 1” or “Stage 4.” But what do those stages really mean?

What Is Endometriosis?

Endometriosis happens when tissue similar to the lining of the uterus (the endometrium) starts growing in places it shouldn’t—like the ovaries, fallopian tubes, bladder, or even the bowel. Unlike the uterine lining, this tissue has no easy way to exit the body during your period, so it builds up, causing pain, inflammation, and sometimes fertility issues.

Who Decides the Endometriosis Stages—and How?

Doctors use a classification system to categorize endometriosis into four stages: minimal, mild, moderate, and severe (Stage 1 through Stage 4). The staging is based on a few key things:

Number and size of lesions
Location of the lesions
Depth of tissue invasion
Presence and severity of scar tissue or adhesions
Whether the ovaries are involved, especially if there are endometriomas (also called “chocolate cysts”)

It’s important to note: the stage does not always reflect the amount of pain someone feels. You could have Stage 1 with intense pain, or Stage 4 and feel very little.

Stage 1: Minimal Endometriosis

At this stage, the disease is just getting started. There may be a few small patches of endometrial tissue, usually on the peritoneum (the thin lining of the pelvic cavity). You might also see some mild inflammation but little to no scarring or adhesions.

Common signs:

Mild pelvic pain, especially during menstruation
Pain during intercourse (dyspareunia)
Some women may not feel any symptoms at all

Because it’s subtle, Stage 1 endometriosis is often missed or misdiagnosed as normal period pain.

Stage 2: Mild Endometriosis

In Stage 2, the patches are more numerous and may be deeper than in Stage 1. Some early scar tissue might begin to form, and there could be minor damage to pelvic organs.

What might change:

Cramps get stronger or last longer
Pain may start occurring outside of your period
Fertility might be slightly affected, though many women can still conceive naturally

This stage is often discovered during diagnostic procedures like laparoscopy if pain or fertility issues prompt further investigation.

Stage 3: Moderate Endometriosis

Now we’re looking at more advanced endometriosis. Lesions are deeper, adhesions may be more widespread, and you might see endometriomas—fluid-filled cysts on the ovaries.

Symptoms tend to include:

Chronic pelvic pain (not just during your period)
Pain during bowel movements or urination
Difficulty getting pregnant
Painful sex

At this stage, endometriosis starts interfering more directly with the function of reproductive organs. Fertility treatments may be needed.

Stage 4: Severe Endometriosis

This is the most advanced stage. Lesions are widespread and deep, with large cysts and thick adhesions connecting organs together. The ovaries, fallopian tubes, bladder, and bowel are often involved.

Women with Stage 4 may experience:

Severe, constant pelvic pain
Fatigue, bloating, and heavy periods
Bowel and bladder issues
Significant infertility

Surgery is more likely to be considered at this point, either to remove lesions, break up scar tissue, or even perform a hysterectomy in severe cases.

So What Stage Am I?

The only way to definitively stage endometriosis is through a laparoscopy, a minimally invasive surgery where a doctor views your pelvic organs with a camera. Sometimes imaging like ultrasounds or MRIs can detect cysts or large lesions, but they don’t show everything.

Endometriosis Diagnosis with a Transvaginal Scan (TVS)

A transvaginal ultrasound (also called a transvaginal scan) can help identify some signs of endometriosis—especially if the condition has caused ovarian cysts (called endometriomas) or deep infiltrating lesions involving nearby organs like the bladder or bowel. But it can’t detect all types of endometriosis.

What Can It Detect?

A skilled sonographer or radiologist can look for:

Endometriomas: These are cysts filled with old blood (“chocolate cysts”) that form on the ovaries. They’re usually visible on ultrasound and can strongly suggest endometriosis.

Deep Infiltrating Endometriosis (DIE): In some cases, the scan may pick up thickened, abnormal tissue between organs, such as the rectum and uterus (rectovaginal septum), or around the bladder.

Organ distortion or adhesions: If organs appear “stuck together” or out of place, that may also be a sign of scarring due to endometriosis.

What Can’t It Detect?

Here’s where the limitations come in:

Superficial peritoneal lesions, the most common type of endometriosis, are usually too small or thin to show up on ultrasound.

The scan might also miss smaller lesions or deep tissue involvement if the operator isn’t specifically trained in endometriosis imaging.

So, if your scan is clear, that doesn’t necessarily mean you don’t have endometriosis.

A transvaginal scan is a first-line, non-invasive tool to look for signs that support a diagnosis of endometriosis. It’s particularly helpful if your symptoms suggest ovarian involvement or deep endometriosis.

But if the scan is inconclusive and symptoms are still suspicious, your doctor might recommend an MRI for deeper tissue analysis, or a diagnostic laparoscopy (a minor surgery where doctors look inside the abdomen with a camera) — this remains the gold standard for confirming endometriosis.

Does the Endometriosis Stage Determine Treatment?

Yes—and no.

While staging helps doctors understand how much the disease has physically progressed, treatment is based more on your symptoms and goals. For instance, someone with Stage 1 but debilitating pain may need more aggressive treatment than someone with Stage 3 who feels fine.

Treatment options may include:

Hormonal therapies to suppress the growth of endometrial tissue
Pain management with NSAIDs or nerve pain medications
Surgical intervention for those with severe lesions or organ involvement

Transvaginal Scan for Endometriosis at Alam Damai Cheras

Get a TVS Scan for Endometriosis with Klinik Azurose

Endometriosis affects an estimated 1 in 10 women of reproductive age—and many go undiagnosed for years. Knowing the stage can be helpful, but it’s not the full picture.

The most important thing? Listen to your body. Advocate for answers. And don’t let anyone dismiss your pain as “just period cramps.” With the right support, endometriosis can be managed—and you can live a full, active life.