Picture a teenage girl who sleeps a lot, even during the during the day, as the whirl of high school activities carry on without her.
Her homework sits waiting for her on a nearby desk or laptop. As the volume of unfinished schoolwork rises, her grades drop. She no longer pursues the activities she once savored.
Some might dismiss lethargy like this as an adolescent phase. Others might suspect depression as the root cause. Few would guess that the actual culprits were blood clots — sticky masses of cells — that had lodged in the girl’s pulmonary artery, starving her lungs of oxygen. She didn’t sleep to avoid the world; she slept to conserve her body’s dwindling energy supply.
Rhiannon Danborn was an athletic, high-achieving 16-year-old when she suffered an artery-blocking clot, called a pulmonary embolism (PE). She ran varsity cross-country and track at Arvada West High School and was looking forward to improving and competing in both her junior year. But no pulse-pounding race of any length could match the challenges and the mysteries that the PE presented.
“I never thought I’d be in a position where something like my breath would be in jeopardy,” Rhiannon said.
Pulmonary embolism at a young age: a relative rarity
Simply developing a PE put Rhiannon in a small club no one wants to belong to. The clots happen to some 900,000 people every year in the United States, but most occur in people ages 60 years or older.
“Pulmonary embolisms are unusual events in people at a young age,” said Dr. Todd Bull, a pulmonologist and director of the UCHealth Pulmonary Vascular Disease Clinic.
Rhiannon’s case was unusual in another respect that prolonged her unexpected struggle with PE, said Bull, who has cared for her since November 2022.
Pulmonary embolism presents another twist
After her PE diagnosis in July of that year, Rhiannon was admitted to a pediatric intensive care unit and treated with blood thinners to prevent new clots from forming.
“We expect that 97% of the time, the clots will resolve,” Bull said. “The body is pretty good at getting rid of them. Our expectation is that within three months, the symptoms will be gone.”
But that didn’t happen for Rhiannon. After treatment, her prognosis initially was promising. Imaging tests seemed to show the PE was gone. But months later, Rhiannon was plagued by shortness of breath, fatigue and brain fog. She had planned to return to running cross-country in the fall and track in the spring, but that goal rapidly fell by the wayside.
“I had to take extra time to walk between classes and up the stairs,” she recalled. “Exercise was completely out of the question. I was exhausted to a level I had never been in my life.”
Bull concluded that Rhiannon is a member of another select group with a condition he says “is not well-appreciated or understood”: post-pulmonary embolism syndrome (PPES). Bull estimated that it affects about 30% of patients who have a PE and receive treatment that appears to have eliminated the clot but who continue to experience shortness of breath, fatigue, and other symptoms at least three months afterward.
“We don’t totally understand why, but [PPES] is a real phenomenon that we are recognizing more and more,” said Bull, who is also a professor of pulmonary sciences and critical care at the University of Colorado School of Medicine on the Anschutz Medical Campus.
With the help of Bull and considerable assistance from the pulmonary rehabilitation team at UCHealth University of Colorado Hospital, Rhiannon is back on track — literally and figuratively. She’s thrilled to be running track again this spring and feels like herself once again.
But her story illustrates how fragile health can be, even in a young person in peak physical condition.
Pulmonary embolism knocks young runner’s life off track
The story of how Rhiannon’s health declined in 2022 can be likened to Ernest Hemingway’s description of how he went bankrupt: “Gradually, then suddenly.”
Her world that spring was bright. She’d run junior varsity cross-country as a freshman but moved to the varsity her sophomore year. She also ran 800-meter and 3,200-meter events in spring track and after working hard at it her freshman year, broke the six-minute-mile mark as a sophomore.
“I liked the competitiveness and was excited to keep improving,” Rhiannon said.
A diagnosis of iron deficiency at the end of May seemed like a minor setback, but she felt more tired than usual when she tried to run harder. At the end of July she summited the twin 14er peaks, Grays and Torreys. They weren’t her first 14er climbs, but she felt surprisingly fatigued and noticed her heart rate was higher than she expected, even with more frequent breaks for one of her friends who was making her first climb.
Three days later, what had been nagging concerns intensified during cross-country practice. She was supposed to run four miles but had to stop after three.
“I knew then that something was up other than the iron,” Rhiannon said. “It felt like when I was trying to run when I had no experience.”
A major health scare with blood clots
The next day, she saw her doctor, who ordered a chest X-ray and EKG, neither of which revealed a problem. But she’d been prescribed oral contraceptive pills with estrogen at the beginning of June, and the doctor who did so recognized that estrogen increases the risk of blood clots. She ordered a test to check for a protein called D-dimer that is made when blood clots dissolve. The test indicated that Rhiannon had blood clots somewhere in her body.
The problems escalated quickly. Rhiannon grew short of breath simply climbing the stairs in her home. Pulling on a shirt was a chore. She had trouble finishing her sentences and felt pressure and tightness in her chest.
The next morning she was in urgent care, where a CT scan showed that a piece of a blood clot had broken free and found its way through her heart and to the point where the left and right pulmonary arteries divide, as Bull described it. The urgent care staff were outwardly calm, but they quickly ordered an ambulance to take Rhiannon to the hospital.
“I didn’t quite realize the gravity of the situation,” she said. That changed when she learned she was headed to the pediatric intensive care unit.
“I knew they don’t put you in intensive care unless you need it,” she said.
An intensive care stay and an ongoing ordeal
Rhiannon spent three days in the ICU as her providers administered and balanced blood thinners to treat the PE. She left the hospital thinking that she would be able to resume running and training for cross-country in a couple of weeks. Instead, she was back in the hospital a week later with persistent shortness of breath. Another hospital stay after she contracted a viral infection followed that one.
As the fall of 2022 progressed, Rhiannon set aside any plans to return to running. She was constantly exhausted, sleeping “a ton,” even without exercising, and her mind clouded. She was taking a tough load of advanced placement classes, including calculus and chemistry, that ultimately proved too much for her.
“Trying to do the work normally would have been a huge challenge, but there was an added layer of brain fog,” she recalled. “I was listening but not retaining information in classes that were heavy on memorization, formulas, and facts, and then trying to apply them.”
She dropped one class so she could end her school day early and return home to sleep. The once-stellar student couldn’t keep up with the work and her grades plunged to Ds and Fs.
“Weekly notices about grades in my email inbox had never happened before,” recalled her mother, Laura.
A medical mystery: where are the blood clots?
Most confusingly, CT scans showed that Rhiannon’s PE had dissolved. She began a frustrating round of inconclusive visits with pulmonologists and cardiologists, all while losing muscle and getting further out of shape.
“I was starting to get a little better but made no progress with my exercise,” she said.
A turning point finally came with a referral to Dr. Dunbar Ivy, director of the Pediatric Pulmonary Hypertension Program at Children’s Hospital Colorado. After examining Rhiannon and conducting an echocardiogram, Ivy found that she was not at risk for chronic blood clots or for pulmonary hypertension – a serious lifelong condition that causes abnormally high blood pressure in the lungs and can lead to right-side heart failure. But he also felt her symptoms indicated something wasn’t right and referred her to Bull.
Major help from pulmonary rehabilitation
That was a turning point. Bull tested Rhiannon to ensure there was no evidence of clots and then cleared her for pulmonary rehabilitation, another unlikely place for a teenager to find herself. At first, the exercise regimen produced yet another scare. Trudging on a treadmill, she experienced heart palpitations. Her heart rate skyrocketed, along with her anxiety and doubts about rehabilitation.
Rhiannon and her therapists — notably exercise physiologist Brian Hemenway—walked a fine line on a path to recovery, said Alexandra Worl, pulmonary rehabilitation coordinator at UCHealth. The challenge: gradually push Rhiannon to higher-intensity exercise without going too far and spurring further bouts of anxiety.
“We needed to reassure her and she needed to reassure herself,” Worl said. “She needed to decrease her stress if she were to improve her rehabilitation. It was frustrating for her because the progress was slow and she wanted to get back to [running]. We reassured her that following the plan would get her there.”
With limits set by Hemenway, in collaboration with Dr. Anne Matthews, medical director of Pulmonary Rehabilitation, Rhiannon slowly made progress. She increased her exercise intensity on the stationary bike and elliptical machine and even lifted weights as a different way to elevate her heart rate and to increase her upper-body strength. She also exercised at home, slowly regaining stamina and confidence.
By February 2023, she finished her three-month pulmonary rehabilitation stint in far better shape than when she had arrived.
“Rhiannon had anxiety because of a traumatic event,” Worl said. “Her commitment to wanting to get back to running and following a home regimen was all (credit to) her.”
For her part, Rhiannon praised the “very supportive atmosphere” that the pulmonary rehab staff provided and the enormous payoff it gave her.
“I walked in not being able to run and walked out being able to,” she said. “It wasn’t just a physical change, but the mental ability to go out and continue to push my body. I felt ready to do it on my own.”
Back to a healthy life as a young teen
Eighteen months after her ordeal began, Rhiannon is back on the path she was following before her PE knocked her off course. Her fatigue and brain fog are gone, and she is running and training with her teammates three times a week. The work paid off in early March.
Running 800 meters competitively, Rhiannon beat the best time she had recorded before her illness.
Her coach, Todd Moore, is now in his 16th year of coaching and coached Rhiannon’s two older siblings. He’s never had an athlete who had to face such a challenging foe as PE. Nor has he witnessed anyone with Rhiannon’s remarkable determination.
“She has the most mental toughness of any human being I have ever seen,” Moore said. “I can’t believe that she continues to push herself with all the difficulties she has had. Most people would have quit,” Moore said.
With the help of tutors and understanding teachers, she’s also restored her grades and is currently first in her graduating class.
Even greater prospects may await. Rhiannon is a finalist for a Boettcher Scholarship, awarded to support high-achieving students who pursue their higher educations at four-year, nonprofit institutions in Colorado.
Rhiannon’s journey back from her health threat holds a wider lesson, Moore said.
“She’s been a very positive influence on others,” he said. “It’s a really good example for others: when bad things happen, don’t give up.”
In turn, Rhiannon’s mother, Laura, believes her daughter has learned from her ordeal.
“Rhiannon had to figure out who she was,” Laura said. “Academics were very hard and she couldn’t run. Sitting with all that, she had to figure out ‘How am I going to be in the world and manage a medical condition and more going forward?’ She doesn’t give herself enough credit for that.”
The road forward
Having survived one dangerous blood clot episode, Rhiannon is at higher risk for another, Bull said. But she is minimizing it by getting off estrogen, and he conducted a test in December called VO2 max to measure her aerobic fitness.
“All aspects of her heart, lung and muscle function are normal,” Bull said. “Her prognosis is excellent.”
To eliminate another potential risk factor, Rhiannon underwent genetic tests to identify possible mutations linked to forming blood clots. A positive finding would mean she would have to take blood thinners the rest of her life, but they found nothing, she said.
Still she looks ahead with an optimism leavened by a healthy respect for the physical and mental challenge she overcame.
“I’m getting back in shape at this point,” Rhiannon said. “I might never feel just like I did before. I am a lot more aware of my body. But I will be running when the season starts.”