May-Thurner Syndrome
May–Thurner syndrome (MTS) is a vascular condition that occurs when an iliac artery (major blood vessel located deep in the lower abdomen and pelvis) compresses an iliac vein (iliac veins run alongside the iliac arteries but in the opposite direction), reducing blood flow from the leg. This narrowing can lead to blood pooling and clot formation, increasing the risk of deep vein thrombosis (DVT). Because it often develops silently, MTS may go undiagnosed until symptoms become more noticeable or complications occur.
Symptoms
Common Signs and Symptoms:
Swelling in the left leg (occasionally both legs)
Heaviness, aching, or throbbing pain in the leg
Leg fatigue, especially after standing or walking
Visible varicose veins or skin discoloration
Warmth or redness in the leg
Recurrent DVT in the same leg
Risk Factors
Factors that may increase the likelihood of MTS include:
Female gender (more common in women between 20–50)
Prolonged immobility or sedentary lifestyle
Pregnancy or recent childbirth
Hormonal therapy or use of oral contraceptives
Family or personal history of DVT or clotting disorders
Anatomical compression (present from birth but may worsen over time)
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