Lung cancer is becoming more common among young, healthy women. Here's why.

Christy Houvouras exercises daily, eats right and has smoked fewer than 20 cigarettes in her lifetime.

That’s why she was shocked when she was diagnosed with lung cancer at just 36 years old in July.

“It was really unfair,” said the mother of two from Huntington, West Virginia. “I do everything I can in my control to take care of myself… It did not make sense that I had something that was associated with an unhealthy person and unhealthy habits.”

Lung cancer is the second most common cancer in both men and women in the United States, according to the American Cancer Society.

Traditionally, this type of cancer is associated with older patients, specifically in men who smoked, said Dr. Iona Baiu, thoracic surgeon at the Ohio State University Comprehensive Cancer Center.