In a fair and just world, potential Hall-of-Famer Chris Bosh would still be playing basketball for the Miami Heat. But in February 2015—Bosh’s first season in Miami without LeBron James — he went to a Miami hospital due to shortness of breath. Doctors discovered a blood clot in his lung (a pulmonary embolism), and Bosh ended up missing the rest of the season. A year later, a second blood clot once again prematurely cut short his season. He hasn’t played in a game since — having failed his physical before the 2016–2017 season—and his condition could be life-threatening if he ever were to return to the court.
For such a non-injury injury — that is, something that doesn’t happen during the course of play — blood clots have become a common malady for professional athletes, no matter the sport. For instance:
- In 2011, tennis great Serena Williams suffered a pulmonary embolism months after a cut on her foot. She required two separate surgeries and was out of action for almost a year. “I was on my death bed at one point — quite literally. I’ve had a serious illness but at first I didn’t appreciate that,” she told The Guardian.
- In 2014, longtime Philadelphia Flyers defenseman Kimmo Timonen is diagnosed with blood clots in both of his lungs and his right leg. After instituting a strict regimen of blood thinners, he’s able to return to the ice and play one last season with the Chicago Blackhawks, winning the Stanley Cup with them before retiring. It should be noted that playing across from Timonen in that Stanley Cup Final was Tampa Bay Lightning Captain Steven Stamkos. The next season, Stamkos himself suffered from a blood clot near his collarbone. After going on a similar blood-thinning regimen as Timonen, Stamkos was eventually able to return to the ice.
- In late 2016, 20-something Cam Bedrosian, the new closer for the Los Angeles Angels of Anaheim, got shut down for the year after he developed a blood clot in his throwing arm. Another young closer, 27-year-old Jeurys Familia of the New York Mets, misses most of this season due to a clot in his throwing arm.
This list, of course, is abridged, but you get the idea.
So what the hell is going on? These men and women represent the pinnacle of physical health. Why then do they seem so susceptible to this particular condition, and why is it apparently getting more frequent? As usual, it’s not just one thing — there are many contributing factors.
Factor #1: Injury and Immobilization
For athletes, these issues typically go hand-in-hand. Injuries that require casting, for example, can lead to clot formation in the legs due to lack of movement. Combine this with the hours upon hours of cross-country travel at high altitudes athletes sit through each year, and even routine injuries can be incredibly risky if not properly monitored.
Factor #2: Supplements, Pharmaceuticals and Dehydration
When you’re dehydrated, your blood can thicken, increasing the risk of clotting. In addition to the intense workout regimens and on-field activity of professional athletes, the supplements and other drugs they’re given by trainers and team physicians play a huge role as well. Case in point: This study demonstrates a link between “venous thrombotic events” and creatine. “Many muscle-building and tone-building supplements include diuretics and other elements that can worsen existing dehydration, and if they also raise blood pressure, it could increase the risk of clotting from a blunt impact,” says Andrew Hill, a Portland-based acupuncturist and massage therapist who specializes in musculoskeletal injuries.
Not surprisingly, more sophisticated muscle-building supplements (aka steroids) are no better. “The increased use of both testosterone-enhancing and anti-inflammatory steroids combined with the higher levels of impact during play as well as more rigorous training styles (like CrossFit) are [also] at least partially to blame,” he continues. “The way those drugs and supplements impact the healing of injuries are more likely to lead to clot formation. When you combine that with the increased damage to the muscle tissue, it leads to a much greater likelihood of proteins and inflammatory agents loose in the bloodstream.”
To be clear, that isn’t to accuse any of the athletes who have suffered from blood clots of using steroids. But they are one potential cause of clotting.
Factor #3: Athlete-Specific Repetitive Motion
For athletes who do the same kind of motion over-and-over (e.g., pitchers), that repetitive acceleration of blood through a narrow passage can encourage clotting near the shoulder, which is what happened with Bedrosian and Familia. Dr. Mary Cushman of the University of Vermont explains:
“Athletes who use their arms heavily, like tennis players, baseball pitchers and basketball players, are at risk of clots involving the arm veins. These clots can occur when a structure at the base of the neck next to the shoulder called the thoracic outlet is narrowed. The vein, artery and nerve supplying the arm has to pass through this outlet, which is lined by muscles and bony structures. For athletes, especially those using their arms, the muscles can get large and contribute to the narrowing of the outlet. In this situation, repetitive injury to the vein going through that narrowed outlet sets the stage for a clot forming in the vein.”
Factor #4: Advances in Technology
While not necessarily a cause of increased blood clots in athletes, advancements in both diagnostic and treatment technology have allowed doctors to detect them earlier and more frequently. The same is true of the general populace, the difference being that the general populace isn’t pushing its mortal limits in the same way.
“Athletes are genetically gifted to perform physical feats, but the physiology of the body is the same for everyone,” Jim Wallis, head athletic trainer at Portland State University, writes to me via email. “If a general public individual has some physiological ailment, say a slight arrhythmia of the heart, it may never be detected since they don’t place themselves in the extremes of their capabilities. Whereas an athlete may do so every day for many years. That’s why for many years, the athlete may not experience any difficulties, then one day, for what reason we do not know, a catastrophic event occurs.”
Wallis also points to our technologically obsessed culture as another reason why we seem to be seeing this problem surface more often: “The 24/7 news-cycle does bring these issues to the public’s attention more quickly. Then the ‘experts’ give their opinion as to the what and why. When more facts are uncovered and the situation is more clearly understood, it’s too late — the story is old news and new news takes center stage.”
Factor #5: Immense Public and Financial Pressure to Perform
Social media doesn’t just put these injuries front-and-center for fans to see; it creates a feedback loop wherein fans can beg, plead and even bully their stars to come back too soon from any injury.
Of course, social media is nothing compared to the pressures of enormous salaries, demands from teammates and ownership, global media scrutiny and their own über-competitive natures. That means even though an athlete may not actually be ready to return to the field, they do anyway. Hill likens it to using spackle on a cracked foundation: “Even though everything look[s] fine, the inherent solidity of the structure [is] actually much weaker. A lot of times these guys will get arthroscopic surgery, which has a faster healing time, but even minor surgery can create clots, so getting them back on the field when they’re pain-free but before they’re totally healed may also be a factor.”
So yes, it’s safe to say that the rate of diagnosis of blood clots in athletes is increasing, but that may actually be a good(?) thing in the grand scheme of things, since it results in more people getting treatment for conditions that they otherwise might not have known about, and that medical professionals are getting better at both diagnosis and treatment all the time.
Which, in the end, might save any one of us — whether we’re blessed with athletic superpowers or not.