DENISON, TEXAS -- Stress can wreak havoc on a student's immune system.
"It's harmful because it lowers our immune system so we're more prevalent to get sick," Denison High School nurse Donna Grubbs said.
When that's paired with a lack of sleep, many teenagers are susceptible to getting ill.
"They don't have the where-with-all to deal with stress, so it affects them negatively," Grubbs said.
A new NPR poll shows that almost 40 percent of parents say their high-schooler is experiencing a lot of stress from school.
Grubbs says students should maintain their mental health by getting plenty of sleep, eating healthy and staying positive.
"Journal! Journaling is something also very beneficial. We are meant to express our feelings, not to suppress our feelings," Grubbs said.
Denison High School Counselor Carrie Boettger also encourages parents to sit down with their student to review and organize all of their tasks during the holiday season, be it test dates, college application deadlines or extra curricular activities.
"Be diligent and be organized. Know when those deadlines are," Boettger said.