You already know how important sleep is and yet it can feel so elusive when you need it the most—which is probably right now, when the holidays are more overwhelming than exciting, work deadlines feel extra tight, and your family’s group chat is going off the rails. But consider this if you’re exhausted: Getting quality sleep (and enough of it) plays a role in keeping your immune health in good shape.
“The immune system, when working correctly, is complex and elegant,” Kara Wada, MD, an allergist and immunologist at The Ohio State University Wexner Medical Center, tells SELF. It’s a smart network of cells, proteins, and organs that can “rapidly recognize what is not welcome” in your body, she explains, including germs that can make you sick. When your immune system detects viruses or bacteria, it typically fires off a swift response to shut down the threat they pose to your well-being.1
How does sleep fit into this process? Even if you’re a generally “healthy” person, here’s what you should know if you’re struggling to get good rest in the thick of cold and flu season.
How sleep supports your immune system
“Sleep is the time when your brain and body are in rest, repair, and recovery mode,” Dr. Wada says. “The quality and quantity of your sleep help keep your body in optimal form and function.”2
While you snooze, your body produces new protective cells as well as proteins called cytokines that help regulate your sleep and immune function, Dr. Wada says.3 Your immune cells then make their way throughout your body, from your blood to your lymph nodes to your organs. “During this migration, the immune cells communicate with one another, playing a game of matchmaker,” Dr. Wada explains. “It is this process that is critical in fighting off infections.”
And all of this is inherently tiring, Otto Yang, MD, an immunologist and the associate chief of infectious diseases at UCLA Health, says. “The cells that are part of the immune system consume a lot of energy to do their job,” he tells SELF.
That’s one reason why fatigue from, say, the flu can hit you so hard and fast. When you’re sick, “your body will actually encourage you to get more rest by increasing signals that promote sleep,” Dr. Wada says.4 And if you’re also wiped out because you haven’t been sleeping well in general, your body may have a hard time dishing out its resources (a.k.a. energy) to your immune response—especially when a strong one is needed to help you recover from a cold, the flu, or another bug.3
So can a lack of sleep increase your chances of getting sick?
Not getting enough sleep does not directly make you sick, but it doesn’t help your immune system’s chances of preventing an infection, according to W. Christopher Winter, MD, a neurologist and sleep medicine physician with Charlottesville Neurology and Sleep Medicine, tells SELF. For example, research has found that people who get fewer than six hours of sleep a night are significantly more likely to catch a cold compared to folks who clock in more than seven hours.5
