How Do I Know if I Have May-Thurner Syndrome?

Written By Center for Vein Restoration
Blog Image May Thurner Syndrome

May-Thurner syndrome is a relatively uncommon vascular condition that occurs when the right iliac artery that carries blood to the lower extremities compresses the left iliac vein against the lumbar spine, leading to reduced blood flow and an increased risk of deep vein thrombosis (DVT). If left untreated, this condition can have a profound impact on an individual's well-being. Learn why this anatomical disorder should be considered for people with unexplained left lower limb pain.

This blog will shed light on May-Thurner Syndrome (MTS), exploring its causes, symptoms, and diagnostic methods to help individuals recognize and address this potentially serious vascular condition.

What is May-Thurner Syndrome?

May-Thurner Syndrome, also known as iliac vein compression syndrome, is a vascular disorder characterized by the compression of the left common iliac vein by the overlying right common iliac artery. In the realm of vascular health, May-Thurner Syndrome (MTS) remains a relatively unknown condition, often overshadowed by more common circulatory issues, such as vascular disease, blood clots, coronary artery disease, peripheral artery disease, and others. Yet, for those who experience its symptoms, MTS can significantly impact daily life.

Per Science Direct, The Journal of Thrombosis and Haemostasias:

“While May‐Thurner syndrome (MTS) was initially presumed to be rare when it was first anatomically defined in 1957, case reports of this syndrome have recently become more frequent, perhaps due to improved imaging techniques allowing for enhanced visualization of the iliac veins. Still, the population burden of this condition is unknown, and there is speculation it may be higher than generally perceived.”

MTS affects blood flow in the legs, accounting for approximately 2–5 percent of lower-extremity venous disorders. MTS occurs when the right iliac artery, which carries blood away from the leg, compresses the left iliac vein, which returns blood to the heart. This compression disrupts blood flow, increasing the risk of developing deep vein thrombosis (DVT), a potentially life-threatening blood clot in the leg.

According to the National Library of Medicine (NIH), despite being shown to be present in over 20 percent of the population, May-Thurner syndrome is rarely considered to be the probable cause of DVT, particularly in patients with other risk factors.

Recognizing the Symptoms of May-Thurner Syndrome

The symptoms of May-Thurner Syndrome can vary, and some individuals may remain asymptomatic (i.e., show no symptoms). However, for those who do experience symptoms, the following signs may indicate the presence of this condition:

  1. Leg Swelling: Unilateral swelling, usually in the left leg, is a common symptom of May-Thurner Syndrome. This swelling may be gradual and could be accompanied by a feeling of heaviness or discomfort in the affected leg.
  2. Pain or Discomfort: Individuals with MTS may experience pain or discomfort in the left leg, often described as aching or throbbing. The pain may worsen with prolonged standing or sitting.
  3. Skin Changes: Skin discoloration, such as a reddish or bluish tint, may occur due to poor blood circulation. Additionally, the affected leg may feel warmer than the other.
  4. Varicose Veins: The development of varicose veins in the left leg could indicate May-Thurner Syndrome. These twisted and enlarged veins may be visible beneath the skin's surface.
  5. Swelling During Pregnancy: Pregnancy can exacerbate the symptoms of May-Thurner Syndrome due to increased pressure on the pelvic blood vessels. Women experiencing leg swelling or discomfort during pregnancy should seek medical attention.

What are the causes and risk factors for developing May-Thurner syndrome?

It's important to note that some individuals may develop the condition without any known risk factors, and these factors do not imply that an individual will develop MTS. However, if you have one or more of these risk factors and suspect you may have May-Thurner syndrome, you must consult a healthcare professional for an accurate diagnosis and appropriate management.

Female sex

The condition is more prevalent in women between the ages of 20 and 45, especially those who are postpartum or have had multiple pregnancies. However, young males should also be considered when presenting with left lower limb pain.

Use of oral contraceptives

Per the National Institutes of Health (NIH), women using oral contraceptives presenting with left-sided iliofemoral DVT should be screened for hypercoagulable disorders(an inherited or acquired condition that increases the risk of excessive blood clot formation) and underlying May-Thurner anatomy.


Individuals with this sideways curvature of the spine that occurs most often during the growth spurt just before puberty are at an increased risk of developing the MTS.


Dehydration contributes to the development of sluggish blood flow and blood clots and is also considered a risk factor for May-Thurner syndrome. Doctors advise drinking eight to ten eight-ounce glasses of water daily for optimal blood flow.

Hypercoagulable disorders

Certain inherited conditions and some cancers can predispose someone to the increased tendency to form blood clots that can contribute to the development of May-Thurner syndrome.

Prolonged immobilization or pregnancy

The syndrome is more prevalent after prolonged immobilization or pregnancy.

How is May-Thurner Syndrome Diagnosed?

If you suspect you may have May-Thurner Syndrome based on the abovementioned symptoms, it is crucial to consult a healthcare professional for a thorough evaluation. Diagnostic methods commonly used to confirm the presence of MTS include:

  1. Doppler Ultrasound:
    • Doppler ultrasound is a non-invasive imaging test that uses sound waves to create images of blood flow in the veins. It is often the initial diagnostic tool to evaluate for blood clots and vein compression.
  2. Venography:
    • Venography involves injecting a contrast dye into the veins and taking X-ray images to visualize the blood flow. This more invasive procedure provides detailed information about the anatomy of the veins and the extent of compression.
  3. Computed Tomography (CT) or Magnetic Resonance Imaging (MRI):
    • CT or MRI scans may be utilized to obtain detailed images of the blood vessels and surrounding structures, helping healthcare professionals assess the severity of vein compression.

What are the Treatment Options for May-Thurner Syndrome?

Once diagnosed, the treatment approach for May-Thurner Syndrome aims to alleviate symptoms, prevent complications, and improve blood flow. The choice of treatment may vary based on the severity of the condition and individual health factors. Common interventions include:

  1. Anticoagulant Medications:
    • Blood-thinning medications, such as anticoagulants, may be prescribed to prevent the formation of blood clots. This approach is often employed for individuals with a history of deep vein thrombosis.
  2. Angioplasty and Stenting:
    • In cases of significant vein compression, angioplasty and stenting may be recommended. During this procedure, a catheter is used to inflate a balloon, widening the narrowed vein, and a stent is placed to maintain the vessel's patency.
  3. Thrombolysis:
    • Thrombolysis involves the administration of medications to dissolve blood clots. This approach may be considered for individuals with extensive clot burden.
  4. Lifestyle Modifications:
    • Adopting a healthy lifestyle, including regular exercise, maintaining a healthy weight, and avoiding prolonged periods of immobility, can contribute to overall vascular health and reduce the risk of complications.

Living with May-Thurner Syndrome

Following your doctor's recommendations and maintaining a healthy lifestyle are crucial for managing May-Thurner syndrome and preventing complications. This includes:

  • Wearing compression stockings: These special stockings can help improve blood flow and reduce swelling.
  • Maintaining a healthy weight: Obesity can worsen symptoms and increase the risk of DVT.
  • Regular exercise: Physical activity promotes blood flow and overall health.
  • Avoid long periods of sitting or standing: Take breaks to move around and elevate your legs whenever possible.
  • Staying informed: Learn as much as possible about May-Thurner syndrome to advocate for your health and make informed decisions.


While potentially serious, May-Thurner syndrome can be effectively managed with early diagnosis and appropriate treatment. Don't hesitate to consult your doctor if you experience any concerning leg symptoms, such as swelling, pain, or persistent fatigue. Early intervention can significantly improve your quality of life and prevent potentially life-threatening complications, such as deep vein thrombosis.

Center for Vein Restoration: Your Vascular Health Partner

Healthy veins are the hidden highways of your body, keeping circulation flowing strong and your health on track! That’s where Center for Vein Restoration (CVR) comes in! We offer personalized vein care, including state-of-the-art diagnostics and cutting-edge vein treatments, so you have the confidence to get back to living life to the fullest.

At CVR, it isn't just about treating veins; it's about empowering your health. So, listen to your veins and take the first step towards better health. Remember, healthy veins mean a happy you!

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