This article is part of Health's series, Misdiagnosed, featuring stories from real women who have had their medical symptoms dismissed or wrongly diagnosed.

Gina Hollenbeck, 43, made it her professional mission as a nurse to help women get the best health care. And even as the working mom of two young boys, she always took good care of her health. So when she developed a cough in June 2015, she took notice.

“I was eating organic, I had recently gone vegan, and I was playing competitive tennis and running half marathons,” she tells Health. “I kept thinking it was kind of strange, I’d cough up gunk but then get better. However, I had run a couple of 5Ks, and my time wasn’t as good as usual. I started to question what was wrong with me."

Toward the end of July, with her cough still lingering, she noticed she was losing weight. Already fit, she didn’t have weight to lose. “The first thing that came to my mind from my medical experience was when you start to lose weight inexplicably, it could be cancer," she recalls.

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Since she didn't have a regular primary care physician, she made an appointment with her ob-gyn. “I told him I thought something was wrong, and could I get a chest X-ray? But he just said, ‘Oh Gina, you’re 38, you’re an athlete, you do everything right. I don’t want to expose you to the radiation. I think this is seasonal allergies.’”

At the time, she thought it made sense. So she started taking allergy medicine and waited two weeks to see if her symptoms improved. But they only got worse. “My cough was becoming a lot more intense,” she says. “Every time I laughed, I would have to cough.”

Certain she didn't have seasonal allergies, she thought it could be pneumonia. So she called an ear, nose, and throat doctor and explained her situation, and that her cough was more intense and her energy levels were down. She was hoping to get a chest X-ray.

“He told me to come into his office, and he looked down my throat and said, ‘You have gastric reflux.’ He gave me acid reflux medication and said to give him a call in two weeks." Frustrated, she followed her doctor’s orders. But a new symptom presented itself in August: a terrible pain in her left shoulder.