Shea Theodore announced this week that he was diagnosed with testicular cancer this offseason. 

The Vegas Golden Knights defenseman penned an essay in The Players' Tribune detailing the diagnosis and his experience throughout the aftermath. Theodore, 24, said the news came after he failed a drug test at the IIHF World Championships in Slovakia this summer, immediately following the Golden Knights' elimination from the Stanley Cup Playoffs. 

According to the defenseman, the positive test was triggered by a hormone called hCG, which is usually only found in women during pregnancy but can be an indicator of testicular cancer.  Theodore traveled back home to the United States, where the cancer was confirmed.

Luckily, the failed drug test helped doctors catch the cancer in its early stages and Theodore underwent successful surgery. He has made a full recovery and will be monitored closely to make sure the cancer doesn't return. Meanwhile, he's ready to begin another season in Vegas. 

In the personal essay, Theodore talks at length about the anxiety he experienced following the diagnosis and how hard it was to open up to family, friends and Golden Knights' teammates. He details some of the support he received in wake of the diagnosis, including a surprise message from Phil Kessel, who was also diagnosed with testicular cancer early in his career. 

But Theodore also uses that essay to urge others -- specifically young men and hockey players -- to be aware of the signs and stay proactive when it comes to monitoring their health. 

Look, I get it. I couldn't even bring myself to tell Phil. I was so worried to let the boys know what was going on with me. We're not the greatest with emotions, are we? We're not the greatest at taking care of ourselves if something isn't obviously broken. But if you're reading this article and you're a young man, I can't stress it enough: 

Know the symptoms. 

At your next checkup, you should ask your doctor if you notice anything. There's no reason whatsoever to be embarrassed. Just DO it — because early detection is SO important. Early detection saved my hockey career. And who knows… if it had spread? I don't even want to think about that…

Theodore also announced that he plans to donate money to early detection causes for every point he tallies during the upcoming season, and the Vegas Golden Knights will match his donations throughout the year.