An unrelated work injury during which a man named Brian broke his hand and hurt his shoulder led to a devastating cancer diagnosis.

Recalling the past couple of years of his life, the 40-year-old man realized he has in fact always experienced symptoms, but they were mild and seemingly harmless.

The work injury required an X-ray that among the rest showed a lung mass doctors believed to be a bruised part.

Further tests, however, revealed he had limited-stage small cell lung cancer. This meant that only one part of his lung has been affected and can be treated with a single radiation field.

According to the American Cancer Society, “This generally includes cancers that are only in one lung, and that might also have reached the lymph nodes on the same side of the chest.”

Taking to YouTube, Brian decided to share his story of how his work injury led to a cancer diagnosis.

“I’d been having this heartburn for years,” he said in a clip of The Patient Story.

“I went to the emergency room a couple of times and I was sure [that] I had cancer, but they assured me that I didn’t.”

Doctors assured him it was just reflux, and according to Brian, he first addressed the issue some three years ago.

He, however, hadn’t experienced any other symptoms. What’s most, he has been working heavy jobs that involved lifting objects and taking 25,000 steps a day, but he still felt fine.

As of now, Brian is undergoing chemo and radiotherapy treatments.

In the clip he shared, he explains that he receives three consecutive treatments followed by 21 days off. He’s also receiving radiation therapy twice a day for five days a week.

Luckily, despite the intensive treatments, Brian isn’t experiencing any serious discomfort.