David Bloom’s sudden death was caused by a ‘silent killer.’ Know the signs

NBC’s David Bloom was on assignment in Iraq when he passed away on April 6, 2003. The war correspondent had prepared for every possible danger, but the way he died shocked his family and the world.

The cause of death was a complication from deep vein thrombosis. A blood clot that started in Bloom’s legs — likely brought on in part by spending long days inside cramped armored vehicles — traveled to his lungs, causing a fatal pulmonary embolism, a sudden blockage in a lung artery.

His widow, Melanie, calls it "the bomb that lay within his own body."

"Just a few days before he died, he called me and told me he was sleeping on tank’s fender because he had leg cramps," she tells TODAY.com.

"He just couldn’t sleep with the shooting pains in his legs. Neither of us realized at the time that these cramps could have been an early sign of deep vein thrombosis."

Bloom, 39, collapsed while embedded with the U.S. military’s 3rd Infantry Division as it rolled north toward Baghdad. He left behind his wife and their three young daughters.

Twins Christine and Nicole Bloom, now 29, and their sister, Ava Bloom, now 23, shared some of his last words to them as they marked the 20th anniversary of Bloom’s death in April 2023.

The year Bloom died, a study showed 74% of Americans were completely unaware of DVT, his widow previously told TODAY.com.

"I had never heard of DVT myself and I don’t think David ever had. The more I learned, the more shocked I was. It wasn’t an IED or a bomb that took his life. It was this DVT,” she said.

Twenty years later, there’s more awareness about deep vein thrombosis thanks to the efforts of his family, who established March as National DVT Awareness Month. His widow has become a leading advocate for spreading the word about the dangers of the condition.

It can happen after a long flight or if you’ve had surgery. Here is what to know about your risk and how to prevent blood clots from developing.

What is deep vein thrombosis?

It happens when a blood clot forms in a deep vein, usually in the lower leg, thigh or pelvis, but sometimes also in the arm, according to the Centers for Disease Control and Prevention.

That may cause permanent damage to the valves in the vein and lead to long-term problems such as pain, swelling and leg sores, the American Academy of Orthopaedic Surgeons warned.

If the blood clot breaks free, it can travel through the bloodstream and block blood flow to the lungs — a rare but potentially fatal complication, the organization noted.

Who is at risk for DVT?

The condition affects up to 900,000 Americans each year, the CDC says.

Blood clots can happen to anyone, but some factors increase the risk such as obesity, older age and a family history of DVT.

The biggest risk factors include:

• Suffering injury to a vein — which can happen during surgery or if you break a bone in your leg.

• Slow blood flow — caused by sitting for a long time, on a transoceanic flight, for example, especially with crossed legs; or being confined to a bed after recovering from surgery or because of another medical condition.

• Increased estrogen — due to birth control pills, hormone replacement therapy or pregnancy.

• Chronic illness — including heart disease, lung disease, cancer and inflammatory bowel disease.

• Clotting disorder — Bloom's autopsy revealed he had factor V Leiden, his widow noted, a hereditary gene mutation that can increase a person's chance of developing abnormal blood clots. The condition is common, Dr. Geoff Barnes, vascular medicine specialist at University of Michigan, said in an Oct. 27 segment on TODAY. One in 20 people who have Western European ancestors could have this inherited disorder, he noted.

• Being dehydrated

What are the symptoms of DVT?

About half of people with deep vein thrombosis have no symptoms, which is why it's been called a "silent killer," according to the National Institutes of Health.

If warning signs do occur, they may include swelling, pain, tenderness and skin redness on the affected part of the body.

"Look for the swelling in the leg or that cramping that you get, especially if it's one leg more than the other," Barnes said. "That could be the blood clot starting in your leg."

It's important to be aware of family history and know if any relatives have had a blood clot, he added.

If a blood clot breaks free, goes up to the lung and causes a pulmonary embolism, the most serious complication of DVT, symptoms may include sudden difficulty breathing, chest pain, coughing up blood, lightheadedness and irregular heart beat. A person with a sudden onset of those symptoms probably needs to go to the emergency room, Barnes said.

How do you prevent DVT?

If you are sitting for a long time — on a trans-oceanic flight, for example — it’s important to get up and move regularly to keep the blood flowing and keep it from pooling in your legs.

“Our calf muscles are a very efficient pump for squeezing the veins and pushing blood back to our heart,” said Dr. Gregory Piazza, a cardiologist at Brigham and Women’s Hospital in Boston, previously told TODAY.com. “When we’re sedentary, we lose that calf muscle pump.”

He recommended getting up and walking at least once an hour, and doing calf exercises and foot pumps to help enhance the calf muscle pump action.

While you’re sitting, the CDC advises raising and lowering your heels while keeping your toes on the floor, then doing the opposite move with heels on the floor.

If you’ve had blood clots before, consider wearing compression stockings, Piazza said.

This article was originally published on TODAY.com