Pelvic Congestion Syndrome
Pelvic congestion syndrome is chronic pelvic pain caused by enlarged, incompetent veins around the ovaries and uterus—essentially varicose veins inside the pelvis. Blood pools in these vessels rather than draining properly, and the resulting distension produces a characteristic pattern of pain: a dull ache that worsens through the day, is aggravated by standing, and eases on lying down. It is one of the more frequently overlooked causes of chronic pelvic pain in women, partly because the veins are invisible on standard examination and partly because the pain is often attributed to other conditions. Recognising it matters, because minimally invasive treatment to close the affected veins relieves symptoms in the majority of appropriately selected women.
What is it?
Blood returning from the pelvis drains through the ovarian and internal iliac veins. Like veins elsewhere, these contain valves that ensure blood flows in one direction—upward and back toward the heart—and prevent it from falling back down under gravity.
Pelvic congestion syndrome develops when these valves fail. Blood refluxes backward and pools in the veins around the ovaries, uterus, and broad ligament. The vessels dilate under the accumulated pressure, becoming tortuous and enlarged, and this distension is what produces pain—stretched vein walls are rich in pain-sensing nerve endings, and the surrounding tissues become congested.
This is the same process that produces varicose veins in the legs, occurring in a location where the result is invisible from outside. The comparison is useful because it explains the pain pattern almost entirely: a woman with leg varicose veins experiences aching that worsens through the day, is worse on standing, and settles on elevating the legs. Pelvic congestion produces the equivalent pattern internally, and this positional characteristic is one of the most useful diagnostic clues available.
Several factors contribute to valve failure.
Pregnancy is the most significant. Blood volume rises substantially during pregnancy, pelvic veins dilate considerably to accommodate it, and the enlarging uterus compresses venous drainage. Vein diameter may not return fully to normal afterwards, and the valves, having been stretched, may no longer close properly. Risk rises with each pregnancy, and the condition is strongly associated with having had children.
Oestrogen contributes independently by relaxing vein walls, which explains why the condition affects premenopausal women almost exclusively and why symptoms typically improve after menopause.
Inherited weakness of vein valves plays a role, and many affected women have varicose veins elsewhere or a family history of them.
Anatomical compression syndromes underlie a proportion of cases and are important to identify because they change treatment. Nutcracker syndrome occurs when the left renal vein is compressed between the aorta and the superior mesenteric artery, obstructing drainage and forcing blood backward down the left ovarian vein. May-Thurner syndrome involves compression of the left common iliac vein by the overlying right common iliac artery, impeding pelvic and leg venous drainage. Both can produce pelvic congestion as a secondary consequence, and treating the ovarian veins alone without addressing the underlying compression may fail or worsen the situation.
The left side is affected more often than the right, reflecting the anatomy of the left ovarian vein, which drains into the left renal vein at a right angle rather than directly into the vena cava, creating a longer column of blood and higher pressure.
The symptom pattern is characteristic once it is recognised, and describing it precisely is the most useful thing this page can do, because the diagnosis is usually made on the pattern rather than on any test.
The pain is chronic, present for more than six months by definition, and is typically described as a dull, heavy, dragging ache or a sensation of fullness and pressure rather than sharp pain. It is most often one-sided, frequently on the left.
The positional pattern is the hallmark. Pain is minimal or absent on waking, builds through the day, and is worst by evening. It is aggravated by prolonged standing, prolonged sitting, walking, lifting, and exercise, and is relieved by lying down. Women often describe needing to lie down by the end of the day, or finding that pain disappears overnight and returns as the day progresses.
Pain is commonly worse in the days before and during menstruation, reflecting hormonal influence on vein distension.
Deep pain during intercourse is very common, and a particularly characteristic feature is post-coital ache—pain that persists for hours or into the next day afterwards. This pattern is unusual in other causes of pelvic pain and is a strong pointer.
Visible varicose veins on the vulva, perineum, buttocks, or upper inner thighs are a significant clue when present, and their appearance during or after pregnancy, or their failure to resolve afterwards, is worth noting.
Other associated features include urinary urgency or frequency, heavy or irregular periods, increased vaginal discharge, lower back ache, and aching or swelling in the legs.
A significant point about this condition concerns its recognition. Chronic pelvic pain in women is frequently attributed to endometriosis, irritable bowel syndrome, adhesions, musculoskeletal causes, or no identifiable cause at all, and pelvic congestion is often not considered. Women commonly report years of symptoms, multiple investigations, and sometimes laparoscopy that found nothing, before the diagnosis is reached. Because the veins collapse when a woman lies flat—which is how she is positioned for both ultrasound and laparoscopy—the condition can be genuinely invisible during the very investigations intended to find the cause. This is a real diagnostic pitfall rather than an oversight, and it is the main reason the condition remains under-recognised.
Diagnosis combines the characteristic history with imaging.
Transvaginal ultrasound with Doppler is the usual first test. It can show dilated pelvic veins, generally defined as exceeding around five to six millimetres in diameter, with slow, absent, or reversed flow. It also assesses the uterus and ovaries and excludes other causes.
The technical caveat matters considerably: scanning a woman lying flat may show normal or minimally dilated veins because they decompress in that position. Assessment during a Valsalva manoeuvre, or with the patient standing or semi-upright where the equipment and setting allow, substantially improves detection. If the clinical picture fits and a flat-lying scan is normal, that does not settle the matter.
CT and MR venography provide a detailed map of the pelvic, ovarian, renal, and iliac veins. Their particular value is identifying compression syndromes that would change the treatment plan, and they are widely used before intervention.
Catheter venography remains the reference standard. A catheter is passed into the ovarian and pelvic veins and contrast injected to demonstrate reflux and dilated collateral vessels directly. In practice it is usually performed at the beginning of the treatment procedure, so that diagnosis and treatment occur in a single session.
Laparoscopy has limited value for this specific diagnosis, for the reason described above—the veins are decompressed by the head-down position and abdominal gas pressure used during the procedure. Its role is in excluding other conditions such as endometriosis, which frequently coexists.
The differential includes endometriosis, adenomyosis, adhesions, chronic pelvic inflammatory disease, interstitial cystitis, irritable bowel syndrome, pelvic floor muscle dysfunction, and musculoskeletal causes. These commonly coexist with pelvic congestion rather than being alternatives to it, and a woman may have more than one contributor to her pain.
Important to Know
Pelvic congestion syndrome is treatable, and the main obstacle for most women is reaching the diagnosis rather than the availability of effective treatment. Care typically involves gynaecology and interventional radiology, ideally working together, with pain specialists and vascular services involved as needed.
A point about validation is worth making directly. Many women with this condition have been told over years that investigations are normal and that no cause can be found, and some have been left with the impression that their pain is not real or is psychological. It is a genuine structural problem with a demonstrable anatomical basis, and it has a specific treatment. Reaching that point often requires persistence, and asking specifically about pelvic vein assessment is reasonable when the pain pattern fits.
Ovarian vein embolisation is the principal treatment. An interventional radiologist accesses the venous system through a small puncture in a vein at the neck or groin, passes a fine catheter into the incompetent ovarian and pelvic veins, and closes them using metal coils, vascular plugs, or a sclerosing agent. Blood then redirects through healthy veins, and the congested vessels decompress.
Reported outcomes are favourable, with most published series describing meaningful symptom improvement in the large majority of appropriately selected women, and improvement often continuing over several months as the veins gradually resolve. The procedure is performed under local anaesthetic with sedation, usually as a day case, with return to normal activity within days.
A realistic caveat belongs alongside those figures. Much of the evidence comes from observational series rather than randomised trials, the selection of patients varies between studies, and outcome measures differ. Recent randomised evidence has produced more mixed results than the observational literature, and the condition remains an area where the strength of evidence does not match the strength of enthusiasm. This does not mean the treatment does not work—clinical experience and consistent series are meaningful—but it does mean expectations should be realistic and that treatment is most appropriate when the clinical picture fits well and other causes have been addressed.
Ovarian function is preserved after embolisation, and the procedure does not cause menopause or prevent future pregnancy, though most women are treated after completing their families.
Complications are uncommon and include coil migration, post-procedure pain lasting a few days, and, rarely, vein perforation. A recognisable post-embolisation syndrome with pelvic ache and mild fever for several days is expected rather than a complication.
Medical treatment with hormonal agents suppresses ovarian hormone production and reduces vein distension. Progestogens including medroxyprogesterone acetate, GnRH analogues, and combined hormonal contraception all reduce pain in trials, and the levonorgestrel intrauterine system is used. These are reasonable first-line options, particularly for women wishing to avoid a procedure or to confirm that hormonal suppression improves symptoms before committing to embolisation. Symptoms typically return when treatment stops.
Where an underlying compression syndrome is present, treating it takes priority. Stenting of a compressed left renal or iliac vein may be required, and closing the ovarian veins without relieving the obstruction can divert pressure elsewhere rather than resolving it. This is the main reason venographic mapping before treatment matters.
Surgery has largely been superseded. Hysterectomy, with or without removal of the ovaries, was historically performed and does not reliably relieve pain—a substantial proportion of women continue to have symptoms afterwards, since the veins themselves remain. It should not be undertaken for this indication without careful consideration.
Supportive measures help many women alongside definitive treatment: avoiding prolonged standing, elevating the legs, compression garments, regular activity, and pelvic floor physiotherapy where muscle dysfunction coexists.
Coexisting conditions deserve attention. Endometriosis, adenomyosis, and pelvic floor dysfunction commonly occur alongside pelvic congestion, and treating the veins will not resolve pain arising from another source. A comprehensive assessment rather than a single-cause approach produces better outcomes, and partial improvement after embolisation may indicate another contributor rather than treatment failure.
Symptoms generally improve after menopause as oestrogen levels fall and vein distension reduces, which is relevant for women approaching that stage when weighing whether to pursue intervention.
Care is best coordinated between gynaecology and interventional radiology, and referral to a centre with specific experience in pelvic venous disease is worthwhile given the variability in how this condition is assessed and treated. Imaging, symptom pattern, and clinical findings are interpreted together, with the positional character of the pain carrying particular weight.
Patient education plays an important role. Understanding that the pain has a structural cause, that the positional pattern is diagnostically meaningful, that a normal scan performed lying flat does not exclude it, that effective minimally invasive treatment exists, that the evidence base has genuine limitations, and that coexisting causes of pain are common all contribute to appropriate care and realistic expectations.
Red flag symptoms include sudden severe pelvic pain, which suggests an acute cause such as ovarian torsion, cyst rupture, or ectopic pregnancy rather than congestion; fever with pelvic pain; abnormal vaginal bleeding, particularly after menopause or after intercourse; unexplained weight loss; a rapidly enlarging abdomen or new abdominal swelling; new one-sided leg swelling, which may indicate deep vein thrombosis; blood in the urine; and any significant change in a previously stable pain pattern. These warrant prompt medical evaluation, as they suggest causes other than pelvic congestion.