Blood Clot in the Legs

Leg Blood Clot Overview

Deep venous thrombosis (DVT) refers to a blood clot embedded in one of the major deep veins of the lower legs, thighs, or pelvis. A clot blocks blood circulation through these veins, which carry blood from the lower body back to the heart. The blockage can cause pain, swelling, or warmth in the affected leg.

Blood clots in the veins can cause inflammation (irritation) called thrombophlebitis. The most worrisome complications of DVT occur when a clot breaks loose (or embolizes) and travels through the bloodstream and causes blockage of blood vessels (pulmonary arteries) in the lung. This can lead to severe difficulty in breathing and even death, depending on the degree of blockage.

In the United States, about 2 million people per year develop DVT. Most of them are aged 40 years or older. Statistics reveal that at least 200,000 patients die each year from blood clots in their lung.

Leg Blood Clot Causes

Three factors may lead to formation of a clot inside a blood vessel.

• Damage to the inside of a blood vessel
  
  
• Changes in normal blood flow, including unusual turbulence or partial or complete blockage of blood flow
  
  
• Hypercoagulability - A rare state in which the blood is more likely than usual to clot

Any component that contributes to 1 or more of these 3 criteria can cause DVT. The more common risk factors are as follows:

• Prolonged sitting, such as during a long plane or car ride
  
  
• Prolonged bed rest or immobility, such as after an injury or during an illness ( stroke)
  
  
• Recent surgery, particularly orthopedic, gynecologic, or heart surgery
  
  
• Recent trauma to the lower body, such as fractures of the bones of the hip, thigh, or lower leg
  
  
• Obesity
  
  
• Heart attack or heart failure
  
  
• Recent childbirth
  
  
• Being at very high altitude, greater than 14,000 feet
  
  
• Use of estrogen replacement (hormone replacement therapy, or HRT) or birth control pills
  
  
• Malignant tumors ( cancer)
  
  
• Rare inherited genetic changes in certain blood clotting factors
  
  
• Disseminated intravascular coagulation (DIC), a medical condition in which blood clotting occurs inappropriately, usually caused by overwhelming infection or organ failure

If you have one DVT, you are more likely than the average person to have a second DVT.

Leg Blood Clot Symptoms

Symptoms occur in the affected leg when a clot obstructs blood flow and causes inflammation. Symptoms may include the following: 

• Swelling
  
  
• Gradual onset of pain
  
  
• Redness
  
  
• Warm to touch
  
  
• Worsening leg pain when bending the foot
  
  
• Leg cramps, especially at night
  
  
• Bluish or whitish discoloration of skin
  
  

Almost 30-50% of individuals have no complaints.