DALLAS — Blood clots don't tend to grab headlines.
Most, after all, are caused by trauma or recent surgery, says Dr. James Kohn, a vascular surgeon on the medical staff at Doctors Hospital at White Rock Lake in Dallas.
So if you've had neither surgery nor trauma, you might assume you're safe. But blood clots, which made news recently when former Secretary of State Hillary Clinton was hospitalized, also occur in otherwise healthy people who have none of the traditional risks. When they do, they can be life-threatening.
Doctors say that problems for Clinton, 65, were related to dehydration and a fall, but not all cases are so understandable.
“Some form and we never have a reason," said Dr. Robin Novakovic, assistant professor in radiology, neurology and neurotherapeutics at the University of Texas Southwestern Medical Center in Dallas.
Such was true for Dallas-area residents Mary Campise and Mike Mig-nardi. Both are runners; both take phenomenal care of themselves. Both had potentially fatal blood clots — technically known as deep vein thrombosis, or DVT — within the last two years.
Although the two are now running again, their experiences have made Campise and Mignardi especially aware of what can go wrong and turned them into crusaders to keep others from experiencing what they did.
“I've become one of those people who, whenever I have a chance, warn others about the dangers," said Campise, who lives in Dallas and is assistant dean of students at Ursuline Academy.
Last year, a few weeks shy of her 48th birthday, she was healthy, “running, biking, doing everything," she said. She had never smoked, never used oral contraceptives — two common risk factors for blood clots. She began having trouble keeping pace with her husband and other people she runs with. They all joked about it, but when she began struggling for breath walking up stairs, she went to her doctor.
He said she might have allergies or exercise-induced asthma. Two weeks later, she woke up, and her left leg was twice the size of her right. Her husband drove her straight to Texas Health Presbyterian Hospital of Dallas, where doctors diagnosed a blood clot.
“You think of a clot being the size of a pea," Campise said. “It turned out once they did the sonogram, mine ran from my belly button to my ankle. It was completely occluded. No blood was coming up or going down."
The danger of a blood clot is what can — and in her case did — happen next.
“Pulmonary embolism is the dreaded complication," Novakovic said. “That's when the clot breaks off and travels back to the heart and lodges in the lung," she said. “If it's not treated or it's big enough, it can lead to heart failure, compromise in heart function, and it can lead to death."
When doctors told Campise she had a PE, or pulmonary embolism, “I asked, 'Isn't that what can kill you?'" she said. “He said the good news is that I had survived the hard part, which is the clot going from the heart to the lungs."
Still, she needed surgery.
“Do I have to?" she asked.
“If not," he told her, “you'll never be able to use that leg again. It will be damaged forever."
Surgery lasted five hours and was followed by bed rest and blood thinners. Doctors told her there was a “95 percent chance" her blood clot was caused by May-Thurner syndrome, in which a vein on the left side is compressed by an artery on the right. Last April, she underwent a procedure to insert a stent into that vein.
“I started walking, then walking farther, then biking," she said. But, she adds, “I was terrified to try. You always worry. I would feel what anybody probably feels when they're running and think, 'Is it a tight muscle or a blood clot?'"
About 18 months after having a blood clot, Mignardi still stands in front of the mirror sometimes, looking at his legs.
“You definitely become a hypochondriac," he said, although he's finished a marathon and runs 20 miles on weekends. “I think, 'Is my left calf larger than my right?'"
It was much larger during late summer of 2011, when Mignardi, an engineering manager who lives in Richardson, Texas, was training for the White Rock Marathon. His leg got to the point where he couldn't run a quarter-mile without feeling like it “would explode," he said. Even walking hurt.
One weekend, he skipped his training runs. Two days later, though, his leg was still swollen. So he drove himself to the emergency room, where doctors found that his entire leg, from the top of his thigh down, was clotted. He didn't have surgery; instead, he was put on blood thinners and confined to bed for a week.
“They knew how to treat it, but they didn't know what caused it," said Mignardi, 53. “I'm all about the root cause. I wanted to know why it occurred to prevent it from happening again."
He did extensive research and learned that clotting occurs when blood is more stagnant and when you're dehydrated. Mignardi travels overseas regularly, thus being immobile for long periods of time. He had never thought much about drinking water, and his pulse rate is low because of all his exercise. Mignardi began to see how he might be a candidate for a blood clot.
During a long flight, Novakovic explained, “we're immobile. The type of circulation in our venous system needs muscle contraction to help the blood move."
Mignardi recently traveled to the Netherlands on business and says he's now “especially cautious" when he flies. “I wear compression socks and drink lots of fluid. I spend more time in the restroom than I used to do. I do little exercises on the plane, things to keep me from being stagnant."
Such incidents even have a name — “economy-class syndrome."
He's written two papers on what he learned, which he's shared with co-workers and friends. Many now wear compression socks when they travel, he says.
Six weeks after he left the hospital, he was running again, but four months passed before his left leg looked like the right again. Neither he nor Campise take blood thinners anymore, and their lives are pretty much back to normal.
Still, says Campise, “needless to say, it was shocking to run one week and almost lose my life the next."