May Thurner Syndrome

A contributor to DVT that can cause deep, throbbing pain

Do you feel persistent leg pain when sitting in a chair? Do your legs ache after driving the car? If you have throbbing or aching leg pain, it’s possible that you could have May-Thurner Syndrome. But you could also have this condition with no outward symptoms at all.


May-Thurner Syndrome (MTS), also known as iliac vein compression syndrome, occurs when the venous outflow of the left lower leg causes swelling, pain, and blot clots in the veins. Patients usually first notice it as a dull or pulsing ache in the lower legs, but some people don’t know they have it until visiting a doctor.

The National Institutes of Health calls May-Thurner Syndrome a “not so uncommon cause of a common condition,” because it is rarely diagnosed but is a common contributor to deep vein thrombosis (DVT). The lesions that form deep within the body aren’t visible to the patient but can be properly diagnosed by Maryland Vascular Specialists.


The symptoms of May-Thurner Syndrome can be similar to other vascular conditions, but it is a distinct diagnosis. A patient usually experiences the syndrome through symptoms like:

  • Swelling, especially in the lower legs
  • Leg tenderness to the touch
  • Skin ulcers
  • A feeling of warmth in the leg, especially the calf
  • Redness or discoloration
  • Enlargement of veins in the leg
  • A deep pulling or tugging feeling in the leg
  • Throbbing or pulsing sensations below the waist
  • Pelvic Pain Pain that radiates to other areas, like the groin

Left untreated, this syndrome can be life-threatening. If a blood clot builds up and breaks free in the body, it can cause a pulmonary embolism that affects your lungs and breathing.

May-Thurner Syndrome


The exact cause of May-Thurner Syndrome is not clearly understood. There is a relationship between it and other vascular disorders, so if you have another vascular disorder, you are more likely to have May-Thurner as well.


May-Thurner Syndrome is found in somewhere between 18% and 49% of patients with lower extremity DVT. The wide range exists because many patients are not officially diagnosed as having May-Thurner Syndrome and may simply be told that they have DVT.

Genetics likely play a role in this syndrome. If you have a family history of vascular problems, you should share this information with your doctor.


May-Thurner Syndrome occurs more commonly in the left lower leg than the right. For this reason, patients often come to their doctor complaining of persistent left leg pain. They may describe leg pain while sitting, lying in bed, or being still for extended periods of time.

Some people don’t have pain but arrive at the doctor due to redness, swelling, or a sensation of warmth. Because these symptoms can be similar to other conditions, a vascular specialist must carefully diagnosis this condition as separate from others.

Diagnosis usually occurs through:

  • CT or MRI scan
  • Ultrasound
  • Venogram, which is like an x-ray of the veins


Traditionally, the treatment for May-Thurner Syndrome was rather invasive and involved clearing the blood clot through endovascular surgery. While this is still sometimes necessary, treatments have evolved over the years.

Today, there are less invasive options for treating May-Thurner Syndrome and preventing your condition from worsening. The main focus is on correcting the underlying compression of the left iliac vein and preventing blood clots.

May-Thurner Syndrome treatment options include:

  • Blood-thinning and clot-busting medication
  • Compression stockings
  • Surgical thrombectomy (clot removal)
  • Tissue sling (a surgery to add a cushion between blood vessels)
  • Angioplasty and a stent
  • Bypass surgery
  • Minimally invasive procedures in an outpatient center
  • Other surgeries suggested by a vascular surgeon


Certain risk factors increase the likelihood that you could develop May-Thurner Syndrome. These include:

  • Having scoliosis
  • Giving birth
  • Having more than one child
  • Taking oral birth control medication
  • Being too dehydrated
  • Having a blood clotting disorder


For good health and peace of mind, schedule a consultation with a MVS vascular specialist to discuss May-Thurner Syndrome. At Maryland Vascular Specialists, we can help you get to the bottom of your leg pain and see what’s causing it.

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