NEW YORK (CBSNewYork) – It’s a wake-up call for young people.

Conditions like stroke, Alzheimer’s disease and gout are typically associated with old age – but now more people in their twenties and thirties are getting diagnosed, TV 10-55’s Katie McGee reports.

Another “old” disease now being diagnosed in younger folks: Osteoporosis.

“When I take care of women in their twenties and she tells me that she had severe low weight, even at a young age, they can develop osteoporosis, ” said Dr. Rick Donahue.

Health experts say less than 50 percent of nine to 12-year-old girls consume the recommended amount of calcium each day – and this is leading to poor bone density earlier in life.

But that’s not all. Doctors say they’re also seeing increased cases of shingles, Parkinson’s disease, gout, even Alzheimer’s.

“The mind needs to be exercised,” said Dr. Donahue. “And we think if it is exercised in a healthy way, it is going to be less apt to have many brain diseases, such as Alzheimer’s.”

While it’s still fairly rare, doctors say Alzheimer’s in younger patients can be more aggressive.

Another early onset condition is stroke, brought on by high blood pressure and cholesterol, doctors say.

But whats behind this troubling trend?

“Because of our unhealthy lifestyle,” said Dr. Donahue. “Kids sitting in front of computers for six to eight hours a day. I am seeing what we used to thing of as old diseases in a younger age.”