Grace goes to the doctor. the doctor tells grace that while her chronological age is 24, her physiological age is 30. what factors could account for this discrepancy?

Stress is the biggest contributor towards this. An overstressed body can contribute toward health problems that are typically present in an older person... Hypertension, Diabetes...

The answer you're looking for is washing your hands. "at this late date, we all expect our doctors to wash their hands before examining us or performing an operation in order to prevent the spread of infection. surprisingly, physicians did not begin to acknowledge the lifesaving power of this simple act until 1847.it was then that dr. semmelweis began exhorting his fellow physicians at the famed vienna general hospital (allgemeines krankenhaus) to wash up before examining women about to deliver babies. his plea was far more than aesthetic; it was a matter of life and death and to prevent a deadly malady known as “childbed” or puerperal (from the latin words for child and parent) fever." 

Health education individuals understand ways to avoid diseases.