Always Sick? It Might Be Your Sleep

Reviewed by Brunilda Nazario, MD on March 17, 2020

Are you feeling a little under the weather? It could be tied to how you sleep.

Studies show that if you don't spend enough time sleeping, or the sleep you get isn't good quality, you're more likely to get sick when you're exposed to something like the common cold or the flu. Not only that, but when you get sick, you may stay sick longer.

Sleep and Your Immune System

What is the connection between sleep and your body's defense against illness and infection? The first thing to know is that it works both ways.

Without good sleep, your body makes fewer antibodies to help you fight infection. It also releases fewer proteins called cytokines. Among other things, cytokines fight off inflammation and infection -- and help regulate your sleep. Fewer antibodies and cytokines give you less ammunition to battle a cold or the flu.

Once you have an infection, your body needs more cytokines than normal to help fight off your illness. If you aren't getting enough rest, your body can't make enough to do what it needs to do to get you healthy. So it can take longer for you to get well.


Scientists aren't sure how or why your sleep changes when you're sick. One theory is that the body tries to get you to sleep more when you're ill so that it can do things to heal itself, such as generate a fever.

The two-way street between your immune system and sleep can be seen with vaccinations. Some vaccines contain weakened bacteria. They are designed to trigger your immune system and prepare it to fight infections when they happen. And research says that vaccines work better when you get enough sleep after you've been vaccinated.

Getting Your ZZZs

Adults need between 7 and 9 hours of quality sleep every night. Teens should get from 8-10 hours. And anyone younger than that should get at least 9 hours (preschoolers and younger, at least 10).

As important as the total number of hours, though, is the quality of your sleep. Snoring and feeling tired throughout the day are just a couple of signs that the ZZZs you're getting may not be good enough.

If you have constant sniffles and think your crummy sleep may be to blame, check with your doctor or a sleep specialist. They can help you make your nights as restful, and as healthy, as they should be.

WebMD Medical Reference



National Institute of Neurological Disorders and Stroke: "Brain Basics: Understanding Sleep."

Colton, HR. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem, National Academies Press, 2006.

Mayo Clinic: "Lack of Sleep: Can It Make You Sick?"

Physiological Reviews: "The Sleep-Immune Crosstalk in Health and Disease."

National Institute of Allergy and Infectious Diseases: "Overview of the Immune System."

Pfluger's Archive: "Sleep and Immune Function."

Nature Reviews Neuroscience: "How (and why) the immune system makes us sleep."

Sleep Foundation: "How Sleep Affects Your Immunity."

CDC: "Vaccines: The Basics," "How Much Sleep Do I Need?" "Key Sleep Disorders," "Sleep and Chronic Disease," "Tips for Better Sleep."

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