"You Be Illin'" is the eighteenth episode of the tenth season of Grey's Anatomy and the 214th produced episode of the series. It is also the 325th produced episode of the Grey's Anatomy franchise. It was broadcast on April 3, 2014.
When one of Arizona's patients brings the flu to the hospital, the infection spreads like wildfire around Grey Sloan Memorial Hospital and the doctor's soon find themselves battling the symptoms while trying to work. The residents find themselves competing to see who will be the first to fall to the virus while Derek finds himself subjected to the flu at the worst possible time as the day of his big presentation on his brain mapping project arrives. Elsewhere, April struggles with how to handle Jackson when he gets ill and their differences start to become apparent while Cristina and Owen team up to work on a pair of sisters who have cardiomyopathy caused by an unknown source, leaving a paranoid Shane to care for Cristina's trial. Callie introduces Jo to the world of orthopedics and helps her work out her frustration in her relationship while, when his student debts begin to pile, Alex finds himself tempted by a new career path when a visiting pediatric surgeon shows him the benefits of life in a private practice.
- "The average person touches their face about eighteen times every waking hour. That leaves you susceptible to infection about one hundred times a day. Infection has a nasty habit of taking advantage of our everyday behaviours. It spreads by touching doors, desks, elevator buttons, pens, sharing cups, even money. All we can do is try our best to prevent it from spreading because once it's our there the infection usually wins."
- "It's a known fact that doctor's make the worst patients. We ignore our symptoms until we're face down on the ground. We like to think we're a different species to our patients but none of us are invincible. Eventually we have to face the fact that we're human and that, sometimes, even the mightiest of us need help."
- "Burning Up" - Magic Wands
- "Atomic Dog" - George Clinton
- "Tenderness" - The Donnies The Amys
- "I Wanna Dance With Somebody" - Bootstraps
This episode's title originated from the song You Be Illin', originally sung by Run DMC.