Pelvic Congestion Syndrome and Endometriosis: How They Differ, and Other Look-Alikes

Pelvic congestion syndrome and endometriosis are two common reasons for long-term pelvic pain in women, and they are easy to confuse. Both can cause aching in the pelvis, painful sex and pain that changes with the menstrual cycle. But they have different causes, are found with different tests and are treated in different ways. This guide explains how they differ, how they can overlap, and how they compare with adenomyosis, fibroids, PMOS (formerly PCOS) and pelvic inflammatory disease.

Two different problems

Pelvic congestion syndrome (PCS) is a vein problem. Veins around the womb and ovaries widen, and their valves stop working, so blood flows backwards and pools. The pooled blood stretches the veins and causes a dull, heavy ache. Read the full overview of pelvic congestion syndrome.

Endometriosis is a tissue problem. Tissue similar to the lining of the womb grows in other places, such as on the ovaries, the lining of the pelvis or the bowel. It reacts to monthly hormone changes, which causes inflammation, pain and sometimes scar tissue. It can also affect fertility.

Both are most common in women of reproductive age, and both tend to improve after menopause. That is part of why they are so often mixed up.

Pelvic congestion syndrome vs endometriosis: telling the pain apart

No single symptom proves either condition, but the pattern of pain gives useful clues.

Pain that points more towards veins:

• A dull, dragging or heavy ache rather than sharp pain
• Pain that builds through the day, or after standing or walking for a long time
• Relief when lying down, especially with the hips raised
• A deep ache that lasts for hours after sex
• Visible varicose veins on the vulva, upper inner thighs or buttocks

Pain that points more towards endometriosis:

• Severe period pain that may start a day or two before bleeding
• Deep pain during sex
• Pain when opening the bowels or passing urine, especially during a period
• Difficulty getting pregnant

For a fuller list of vein-related symptoms, see the symptoms of pelvic congestion syndrome. If sex is the main problem, our guide to pain during or after sex covers the many possible causes.

Can endometriosis cause pelvic congestion syndrome?

There is no proof that one causes the other. However, specialists increasingly recognise that the two often occur together. A 2026 review written for gynaecologists noted the frequent overlap and warned that doctors who find one condition may stop looking for the other.

Possible reasons for the overlap include the role of oestrogen in both conditions, and the fact that both affect the same age group. Researchers have suggested the two may influence each other, but this is still a theory. The practical point is simple: having one does not rule out the other.

Why a normal laparoscopy does not rule out pelvic congestion

A laparoscopy is keyhole surgery in which a surgeon looks inside the pelvis with a camera. It is the most reliable way to confirm endometriosis, and it allows the surgeon to remove patches of it at the same time.

It is much less useful for pelvic veins. During the operation the tummy is inflated with gas and you are tilted head-down. Both of these squeeze blood out of the pelvic veins, so widened veins can look normal. Many women with pelvic congestion have been told their laparoscopy was “clear”.

Pelvic veins are better shown by venous imaging:

• Transvaginal duplex ultrasound, which shows vein width and the direction of blood flow. See what a pelvic venous ultrasound involves.
• CT or MR venography, which maps the veins and looks for compression higher up.
• Venography, an X-ray of the veins with contrast dye, usually done at the time of treatment.

Our guide to how pelvic congestion syndrome is diagnosed explains each test. Some causes of pelvic pain, such as small patches of endometriosis, do not show on scans at all, so a normal scan is not the end of the story either.

Comparison table: PCS and its look-alikes

This table shows typical patterns. Real symptoms vary, and many women do not fit neatly into one column.

Pelvic congestion syndrome vs adenomyosis

Adenomyosis is tissue like the womb lining growing into the muscle wall of the womb. It typically causes heavy, painful periods, and the womb may feel enlarged and tender. Like pelvic congestion, it can cause a heavy, dragging feeling and is more common after pregnancy. The key difference is that adenomyosis pain is closely tied to periods, while vein pain is tied to posture and time of day. An ultrasound or MRI usually shows the change in the womb wall.

Pelvic congestion syndrome vs fibroids

Fibroids are non-cancerous growths of womb muscle. Many cause no symptoms. Larger ones can cause heavy periods, a feeling of pressure, needing to pass urine often, or constipation. They are usually easy to see on a standard pelvic ultrasound.

One point causes confusion: uterine fibroid embolisation blocks the arteries feeding a fibroid, while embolisation for pelvic congestion closes faulty veins. They are different procedures for different problems.

Pelvic congestion syndrome vs PCOS (now PMOS)

The NHS now uses the name polyendocrine metabolic ovarian syndrome (PMOS) for the condition previously called polycystic ovary syndrome. It is a hormone condition that causes irregular periods, extra hair growth, acne, weight changes and difficulty getting pregnant. It is not mainly a pain condition.

Some studies have found ovaries with a polycystic appearance more often in women with pelvic congestion, and some sources list PMOS as a possible risk factor. The link is not fully understood. If you have PMOS and a heavy pelvic ache that is worse with standing, it is reasonable to ask whether veins could be involved.

Pelvic congestion syndrome vs PID

Pelvic inflammatory disease is an infection of the womb, fallopian tubes or ovaries, often caused by a sexually transmitted infection. Signs include lower tummy pain, pain during sex, bleeding after sex or between periods, unusual discharge and sometimes fever. It needs prompt antibiotics, because untreated infection can lead to long-term pain and fertility problems.

Pelvic congestion does not cause fever or discharge. New pelvic pain with these signs should be checked quickly for infection, not put down to veins.

Getting the right diagnosis

Because these conditions overlap, and more than one can be present, a good assessment usually includes:

• A detailed history, including when the pain is worse and better
• A pelvic examination and, where appropriate, swabs for infection
• A pelvic ultrasound looking at the womb and ovaries, and a duplex scan looking at the veins
• MRI or laparoscopy if endometriosis or adenomyosis is suspected

It often takes a gynaecologist and a vein specialist working together. If you are not sure where to start, see which specialist treats pelvic congestion. A Singapore vascular surgeon’s article on symptoms and diagnosis gives another view of how pelvic congestion is investigated.

When to see a doctor

See a doctor if you have pelvic pain lasting several months, pain that affects sex, work or sleep, very painful or heavy periods, or difficulty getting pregnant. Keeping a simple pain diary, noting the time of day, your position and your cycle, can help your doctor spot the pattern. Our pelvic symptom check can help you organise your thoughts before an appointment.

Get urgent medical help for sudden severe pelvic or abdominal pain, pelvic pain with fever or unusual discharge, heavy vaginal bleeding, fainting, or pain or bleeding when you might be pregnant. In Singapore, call 995 in an emergency.

This article is general information, not personal medical advice. Please speak to a doctor about your own symptoms. How we create our content.