(Aging Untold) - When you picture a caregiver, you probably imagine a middle-aged adult or a spouse.

But a new study from the Johns Hopkins Bloomberg School of Public Health shows that role is starting much earlier - an estimated 1. 6 million teens ages 15 to 18 and 2 million young adults ages 19 to 22 are now caregivers in the U.S. An estimated 1. 6 million teens ages 15 to 18 and 2 million young adults ages 19 to 22 are now caregivers in the U.S., according to the Johns Hopkins Bloomberg School of Public Health.(Aging Untold)Why so many young people are stepping into caregiving roles "One of the main drivers is people are waiting to have their children until a much older age," Sam Cradduck, a gerontologist, said.

"You could be a 20-year-old and your parents are in their mid- to late-60s, and that's unheard of in our generation." Cradduck said the strain often doesn't stop there.