When pediatrician Curtis A. Johnson, MD, a senior attending physician at Saint Barnabas Medical Center, reflects on his 28-year career in private practice serving New Jersey’s urban communities, one growing trend alarms him the most: Millions of kids today are being struck by illnesses typically found among their parents and grandparents.

“In urban communities, obesity and high levels of cholesterol and triglycerides are rampant, as well as an increase in the number of diabetes and high blood pressure diagnoses in children,” Johnson says.

Today, like Johnson, more and more pediatricians report seeing a disturbing increase in the number of children with type 2 diabetes, a disease usually diagnosed in adults 40 or older. Part of the uptick, Johnson explains, is due to better diagnostic tools. But doctors say the root cause is obesity, which puts overweight children at an increased risk of type 2 diabetes, coronary heart disease, hypertension, gallbladder disease, osteoarthritis and some cancers.

Currently, 12.5 million American children ages 2 to 19 are obese. But other factors also put kids at an increased risk of adult health problems. Examples include poverty, inactivity, stress, exposure to diabetes before birth and lack of access to health care—factors that can affect kids in both rural and urban homes.

This is illustrated in Amaranthia, a girl whose family has a history of high blood pressure. She was diagnosed with the illness at age 9. She wasn’t obese or overweight, but, according to her mom, docs said a high-salt diet, stress and anxiety caused her condition—now managed with diet, exercise, meditation and her passion, creating artwork. (Mom says meds may be needed later.)

Stress is also linked to kids having health issues common among adults, says Susan Bartell, PsyD, a parenting psychologist, WebMD online adviser and the author of several books, such as The Top 50 Questions Kids Ask series. Parents need to be aware of signs of stress in children, such as sleeping problems, crying easily, anger, withdrawal, eating unhealthy foods and refusing to do homework. Talk with children about their feelings, Bartell suggests, because sometimes kids don’t tell you that they’re stressed.

To address this and other unhealthy factors, parents must become better role models, she says. “If you are smoking or drinking a lot, realize your children see that, and you need to adopt healthy behaviors,” she advises.

Still, kids do have one big advantage when facing adult illnesses. Notes Johnson: “Because of a child’s age, some conditions can be corrected and reversed.”