If it seems like you’re entering yet another holiday season feeling ill and rundown, it’s not all in your head. Doctors say the stress of the holiday season can raise the odds you’ll get sick.
That includes everything from viral illnesses to allergic reactions, Rita Kachru, MD, an allergist and immunologist at UCLA Health, tells SELF. If you feel a little frazzled over a pre-holiday work deadline, Dr. Kachru says you’re unlikely to end up getting sick from that alone. But if you’re constantly struggling with the onslaught the holiday season brings, you—and your immune system—could end up paying for it. Here’s why.
The stress-immunity connection is real.
When you’re stressed or in a pressure cooker situation, your body releases hormones like cortisol and adrenaline to help you get through the moment, Kara Wada, MD, an allergist and immunologist in Ohio, tells SELF. “That’s useful in short bursts,” she says. In fact, smaller bursts of stress can enhance your immune system and increase your protection against infection, Thomas Russo, MD, professor and chief of infectious disease at the University at Buffalo in New York, tells SELF.
But that’s what happens when you have a little stress here and there—chronic stress is a different story. “When we are stuck in survival mode, persistently elevated cortisol levels can disrupt the way immune cells communicate with each other, making your first-line defenses slower and less coordinated,” Dr. Wada says. “It can also weaken protective barriers in places like your nose, throat, lungs, skin, and gut—areas where your immune system works the hardest.”
Chronic stress can also raise the risk of more severe allergic reactions. “Allergens by definition are harmless, but our immune system looks at them as if they’re harmful and mounts a reaction,” Dr. Kachru says. “Chronic stress decreases your immune system’s ability to see if something is harmless or not.”
Chronic stress can also increase inflammation in the body while working against pathways that help to keep allergic reactions in check, Dr. Wada says. “That combination leaves your immune system more prone to making mistakes,” she says.
Because stress has the potential to interrupt sleep and sleep is crucial for your immune health, you can wind up in a bad cycle, per Dr. Wada. “More stress leads to worse sleep and subsequently, a less resilient immune system,” she says.
What does this look like?
There are a few things that can happen as the result of all those stress-induced immune changes. “People often notice they get sick more easily during times of prolonged stress—colds that linger for weeks on end, recurrent sinus infections, or a general feeling that your body just can’t catch a break,” Dr. Wada says.


