Deep vein thrombosis (DVT) is a condition that occurs when a blood clot forms in a vein deep inside a part of the body. It mainly affects the large veins in the lower leg and thigh, but can occur in other deep veins, such as in the arms and pelvis.

DVT is most common in adults over age 60 but can occur at any age.

Blood clots may form when something slows or changes the flow of blood in the veins. Risk factors include:

• A pacemaker catheter that has been passed through the vein in the groin
• Bed rest or sitting in one position for too long, such as plane travel
• Family history of blood clots
• Fractures in the pelvis or legs
• Giving birth within the last 6 months
• Pregnancy
• Obesity
• Recent surgery (most commonly hip, knee, or female pelvic surgery)
• Too many blood cells being made by the bone marrow, causing the blood to be thicker than normal
• Having a long-term catheter in a blood vessel

Blood is more likely to clot in someone who has certain problems or disorders, such as:

• Cancer
• Certain autoimmune disorders, such as lupus
• Cigarette smoking
• Conditions that make it more likely to develop blood clots
• Taking estrogens or birth control pills

Sitting for long periods when traveling — particularly on long car rides or flights — can also increase the risk for DVT, especially for those with additional risk factors like the ones listed above. To help prevent DVT, avoid sitting still for long periods, stay hydrated, and talk to your healthcare provider about whether compression stockings or preventive medication are right for you.

Signs & Symptoms

DVT mainly affects the large veins in the lower leg and thigh, most often on one side of the body. The clot can block blood flow and cause:

• Changes in skin color (redness)
• Leg pain
• Leg swelling (edema)
• Skin that feels warm to the touch

Diagnosis

A Deborah Specialty Physician will perform a physical exam. The exam may show a red, swollen, or tender leg.

The two tests that are often done to diagnose a DVT are:

• D-dimer blood test
• Doppler ultrasound exam of the area of concern

Blood tests may also be done to check for an increased chance of blood clotting, including:

• Activated protein C resistance (checks for the Factor V Leiden mutation)
• Antithrombin III levels
• Antiphospholipid antibodies
• Complete blood count (CBC)
• Genetic testing to look for mutations that make you more likely to develop blood clots, such as the prothrombin G20210A mutation
• Lupus anticoagulant
• Protein C and protein S levels