When a Cramp Is Actually a Clot
Deep-vein thrombosis is often mistaken by both patients and doctors for something else. I was suspicious of what I thought was a runner's cramp, and got lucky.

A glutton for good running weather, I could not resist the Thanksgiving-weekend weather. It was pitch-perfect: cloudless, warm, a cool breeze. The month before I had run my fastest marathon: just under four hours at the 2012 Marine Corps Marathon. So, I should have been recovering with light, slow, shallow runs.
But several hours on a cramped five-hour flight the night before had me buzzing with pent-up energy. So, I ran. Probably too far, probably too fast.
Sitting at a table in Starbucks on Saturday, Sunday, and Monday, plugging away all day on a project, time slipped by. It felt good to focus, all that energy cleared from my metabolic cache. When I stood to go home Monday night, my calves immediately tightened. The pain in the right calf eased, but the pain in the left calf did not.
I rested, iced, elevated the leg, and doubled up on liquids and bananas, but the pain did not subside. On Wednesday, I limped to work and trolled sports-medicine web pages. One website after another said generally the same thing: A deep-vein thrombosis (DVT), or blood clot, can closely resemble a leg cramp or a muscle tear. My stomach clenched.
Recent long travel; a prolonged period of remaining in the same position; and red, painful, swelling were among the causes and symptoms listed. I had all but the redness and swelling. I called my doctor. She said to go to the nearest emergency room. I meant to sound matter-of-fact when I told my boss why I was leaving early, but it came out more as a warble.
The emergency room’s ultrasound technician’s questions turned to silence as she tapped buttons on a keyboard and stared at the images on her screen, rarely looking up as she moved her wand over the clear jelly-like coating she’d smeared on my leg. When she stepped out of the room, I peeked at the images on her computer screen. I saw blue and grey shapes and a small red mound, like an ant hill.
It’s probably a muscle tear, the student doctor said. He came to prepare my history for the ER doctor. It would take a longer flight and longer period of immobility than a weekend at Starbucks to develop a DVT, he said. I was ready to believe him and would have, if it weren’t for that little red mound.
I was poking my leg to pinpoint the pain for the cheery nurse who’d come to check my vitals, when the ER doctor came in. He told me to take my hand off of my leg and not to do that again.
An estimated one in 1,000 Americans are diagnosed each year with a DVT, according to the Centers for Disease Control and Prevention. The number of Americans with DVTs, including those undiagnosed, is estimated to be up to 600,000. As many as 100,000 deaths each year are directly or indirectly linked to a DVT.
Though I have flown farther and sat still in coffeehouses for longer in the past, the doctor told me the blockage most likely was the result of my weekend sojourn in Starbucks, exacerbated by the flight. I might also have been a bit dehydrated from the travel and the run.
Whatever my particular cocktail of factors, the effect was the same: Blocked, the blood built up along the walls of the vein, clotting. Similar to a crash on a highway, the clot slowed the blood that tried to snake around it. The blood piled onto the clot, making it bigger and the passageway narrower.
A DVT is not usually life-threatening, by itself. But if part of the clot breaks loose and is thrown back into the bloodstream to travel freely, eventually it may lodge in a passageway too small for it, such as those found in the lungs. The result, a pulmonary embolism (PE), can kill you.
More than one-third of DVT patients have PE’s, according to the Surgeon General’s Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism, issued in 2008. “Often, the first symptom of DVT is a fatal PE,” Dr. Elizabeth G. Nabel, director of the National Institutes of Health’s Heart, Lung, and Blood Institute, wrote in the report.
DVT/PE is an underappreciated problem in our society, says Dr. Anthony Venbrux, a professor of radiology and surgery and the director of the vascular and interventional radiology division at the George Washington Medical Center, echoing the report’s findings.
“We tend to dismiss them, saying ‘I’ll take an ibuprofen or use a heating pad.’ We, meaning everyone, including physicians,” Venbrux says. “A classic example is a physician who was an athlete and didn’t want to acknowledge that it was DVT in the upper extremity that he was experiencing.”
Early diagnosis is the key to a positive outcome, and diagnosis is not difficult or painful. Now, completely noninvasively, we can rule in or rule out a DVT with 98 percent accuracy using a Doppler ultrasound, Venbrux says. “In the old days, we would have to inject contrast dye.” Nonetheless, many DVTs are believed to slip through the cracks, dismissed or unrecognized.
“The tragedy of these diseases is that their diagnosis is easy to overlook because the signs and symptoms are often diffuse and difficult to recognize. In many cases, there are no clinically apparent signs at all,” Nabel says.
As I quickly learned, the default treatment is to let nature takes it course, assisted by an intense, steady regimen of blood thinners, which rob the blood of its ability to stick to the little red mound, which my body would slowly absorb. The flip side was that my blood also could not stick together well enough to scab should I sustain a bleeding injury.
Around that time, I also discovered ClotConnect.org, which held a wealth of understandable information on blood clots for patients and doctors. Beth Waldron, the program director of Clot Connect at the University of North Carolina Hemophilia and Thrombosis Center, herself had a DVT and two PEs in 2003.
By her own account, Waldron thought she pulled a muscle in the gym. She went to the doctor and was prescribed muscle relaxers. When the pain continued, she tried to work through it until, walking up the stairs to the shower one day, she couldn’t catch her breath. “The world went floaty,” she says.
Eventually, she was prescribed antibiotics for a respiratory infection, she says. But, after taking her antibiotics for five days, under the impression that this wasn’t serious, Beth had a pulmonary embolism that “was off-the-chart painful,” she says. At the hospital, they found a pulmonary embolism in each lung and a DVT from mid-calf to her hip. She was in the hospital for nine days and because the doctors found that she has a genetic risk factor, she is now on blood thinners for life.
“About half of those who develop [DVT/PE] have two things in common. First, they have one or more identifiable risk factors for the disease. Second, they experience some sort of triggering event, such as hospitalization, trauma, surgery, or a prolonged period of immobilization,” the surgeon general’s report said. The other half of cases are mostly unprovoked, or “silent,” producing “few, if any, symptoms,” it said.
In Venbrux’s experience, a “normal patient is someone who comes in with pain and may or may not have swelling. Every one of them says, ‘I thought I turned my ankle or slept funny or pulled a muscle.’ Almost every one of them tends to dismiss or blow off what it is. Almost everyone discounts it initially and then after the diagnosis comes to an awareness,” he says, and noted that physician awareness is equally important.
Nowadays, blood-clot surveillance in hospitals is a standard of practice that “is on the tip of most people’s tongue,” according to Dr. Gregory Piazza, a Harvard Medical School instructor and a physician in the Brigham and Women’s Hospital’s Cardiovascular Medicine division. This development is owed, in part, to reports and studies such as the surgeon general’s report that found that hospitals often failed to identify and begin treating DVT/PE risk early.
Brigham and Women’s Hospital uses a computerized decision-support program to evaluate the risk of every patient in the hospital, Piazza says. The system uses electronic health records to look at risk factors and tabulates a score for each patient. For patients who are high risk, an electronic alert goes to the health-care provider that comes up when admission orders are being written, along with a template of commonly used prophylactic measures, according to Piazza, who also is on the board of directors of the North American Thrombosis Forum.
An electronic decision-support system “is not the norm quite yet,” Piazza says. “Others use simple paper and pencil and tabulate. The important thing is that immediately on admission you get the ball rolling,” he says.
By New Year’s, I had read my way through most of the online literature about DVTs. Beyond the basics, the internet was an information wasteland. My concern that I might develop a pulmonary embolism was shifting into anxiety about the road ahead if I made it through this.
Running was not an option, but neither was sitting still, just worrying and waiting. Hunkered into big jackets weighed down by pockets filled with pills, granola bars, and apple juice, with a medic-alert bracelet clamped on, I spent the winter weekend afternoons on long, slow walks.
After about three months, under the watchful eyes of the neighborhood YMCA’s staff, I ventured into more rigorous activities. If I could manage a cause to bleed on a stationary recumbent bike, I probably deserved an award, I figured. Having read that exercising while on blood thinners might reduce the pain and swelling that sometimes follow a blood clot, it was my mission to become a gym rat. Plus, the Y had cable.
So I pedaled, then I paddled, then climbed, then rowed, and then, with care, stepped into a yoga studio.
Finally, a month out from the end of my six-month blood thinner regimen, it was time to see a specialist to help me resolve this once and for all: Was the clot gone? Could I come off the blood thinners? Would I get another one? Could I run? I told myself I wouldn’t run as long as I had a real fear that I could not distinguish a cramp or a tear from a DVT.
The specialist ordered three tests. The first, a Doppler ultrasound, confirmed that the blood clot in my calf was gone. The second test, a veinous insufficiency study, confirmed that the walls and valves of the vein were undamaged by the clot, which meant I was unlikely to have recurring aches and pains and less likely to develop another blood clot. For the final test, I was sent to a hematologist who took blood to identify any inherited blood factors that could increase the likeliness of another DVT. He found only one, minor genetic risk factor.
Overall, the news was good: no clot, no damage. Even finding I had a genetic risk factor was good news insomuch as we could note it in my medical records, and I could pass along information to my parents that one of them also carries the risk factor, which might be useful, considering that the incidence of DVT and PE increases with age, the surgeon general’s report said.
Knowing the clot is gone and that a small chance exists of developing another one left me uncertain about whether to return to running. On the one hand, getting figuratively kneecapped by a scary Scrabble word leaves an impression, and I often wonder what might have happened if not for that gut-instinct search for “calf tear.”
On the other hand, there is great relief knowing that, after years of listening to and interpreting my body’s signals as a runner, when I thought something was amiss, something was.
There was no easy answer. If you’ve had one DVT, your odds increase of getting another, more so if you have a genetic risk factor. But many factors are in play, some of which I can control.
I move around as much as possible. I wear seriously unsexy, but comfortable compression stockings to improve circulation in my legs when I am on my feet or sitting for long periods. And I keep up the activities that served me well as I recovered: yoga, swimming, bicycling.
In June last year, for the first time in six months, I ran. I ran slowly, carefully, self-consciously. I ran into some old and to-be-expected aches and pains, and I met some new ones. And anxiety was out on the trail too. But that day, I ran past it. Now, I don’t see it so often anymore. And last November, I ran the Marine Corps Marathon again, finishing with a new fastest time.