The death of NBC correspondent David Bloom and last winter’s hospitalization of Kentucky Gov. Ernie Fletcher have made people aware of the serious, but preventable condition known as deep vein thrombosis—or DVT.

Western Baptist Hospital vascular surgeon Michael Jones, M.D., said even more people need to know about DVT and how to prevent

“The medical community needs to raise awareness about the signs, symptoms and risk factors associated with DVT,” said Jones, “and to educate the public that this condition is preventable.”

Silently and often with little or no warning, DVT affects as many as 2 million Americans annually. It occurs when a blood clot forms in one or more veins in the leg.

Over time, it can cause leg pain and swelling and can sometimes have deadly consequences. The blood clot can break away from the leg vein and travel to the blood vessels that supply the lungs. Left untreated, this condition, called a pulmonary embolism, can be fatal in as many as one out of four people.

Here are the risk factors:

• Age over 40 years old
• Prolonged immobility or paralysis
• Surgery, especially orthopedic, pelvic and abdominal operations
• Trauma—up to 60 percent of patients with leg fractures
• Prior DVT
• Cancer, particularly ovarian, pancreatic, lymphatic, liver, stomach and colon
• Inherited clotting disorders
• Hormone replacement therapy and birth control medications

Medical conditions affecting mobility, such as heart failure, chronic respiratory failure and even pregnancy, can also elevate risk.

Jones said symptoms are not always obvious, but may include:

• Deep muscle pain
• Muscular tenderness
• Swelling or tightness
• Discoloration of the affected area
• Skin that feels unusually warm

“If any of these warning signs appear, see your physician immediately,” said Jones. “Timely treatment can reduce the chances of developing a pulmonary embolism to less than 1 percent.”

Blood tests, ultrasounds, MRIs and other tests can help doctors diagnose DVT. If doctors detect a clot, treatment can help prevent it from getting larger or from traveling to the lungs.

Treatment may include blood-thinning medicines called anticoagulants. Other medicines can help dissolve the clot. Sometimes, other interventions are needed to remove the clot from a vein.