Sleep & Your Immune System: How Do They Correlate?

You go to bed late, toss and turn all night, and finally fall asleep—but the morning comes quickly. We know that groggy, cranky feeling all too well. Carrying on with the day's tasks after a short night of sleep is no easy feat. Have you ever wondered how a bad night (or multiple nights) of sleep can impact your overall health? 

 
How does the immune system operate? 

The immune system is a delicate and complex balance of multiple lines of defense against illness. When it is threatened, the immune system triggers a host of responses, which include redness, pain, fever, fatigue, and inflammation or swelling. While it’s important to build a strong immune system through multivitamins, good food and exercise, you must also keep your body well-regulated so that the immune system does not go into attack mode. Getting good sleep regularly is imperative in order to keep your body regulated and healthy. 
 

Can a lack of sleep make you sick? 

As you may have experienced in the past, sleep and the immune system have a bidirectional relationship. Immune responses or illnesses can impact sleep, while sleep strengthens the immune system, helping to protect the body against illnesses. When you don’t get enough sleep, both on a long- and short-term scale, your immune system can be thrown off. 
 

What happens to your immune system at night? 

When you sleep, your immune system’s memory is being strengthened. Experts don’t know exactly why this process happens, but they speculate that there are several involved factors: 

1. Melatonin, a sleep hormone that your body produces at night, counteracts the stress that comes from inflammation 


2. Breathing and muscle activity slows down during sleep, which frees up energy for the immune system to perform other tasks 


3. Inflammation that happens during the nighttime could be harmful to physical and mental performance if it happened during waking hours, so the body processes during the night 



During sleep, your immune system releases proteins called cytokines. Some cytokines help to promote sleep while others are needed when your body is undergoing inflammation or stress. Sleep deprivation decreases the production of cytokines that are necessary to protect your body from illness. Antibodies are also reduced when you don’t get enough sleep. When the body doesn’t receive enough sleep, it takes control to fight sickness, making you feel like you need to sleep in later or take a nap. Sleep is a necessary component of building up the body’s immune system. 

When you’re feeling under the weather, its common to be told to “get some rest”. By getting enough sleep, you’re enabling your body to have a well-balanced immune system. Therefore, sleep disorders, such as insomnia and sleep apnea can be very serious as they can disrupt a healthy immune system. 
 

How many hours of sleep is optimal for a healthy immune system? 

Experts say that seven to eight hours is enough for adults, teenagers need nine to 10 hours and school aged children need 10 or more hours of sleep. Here is a sleep chart with the recommendations from the National Sleep Foundation: 
 

 
How else can I optimize my sleep? 

There are several ways to optimize your sleep schedule. Experts say that maintaining a regular bedtime and waking time can be helpful (if you’re looking for a way to manage the sleep schedule of your growing infant, we suggest using the Nanit Sleep Schedule Generator). Napping to reduce daytime fatigue is also important-- just don’t let napping replace a full night of sleep. Try to cut back on caffeine and alcoholic beverages, especially at night, and limit the consumption of sugar-sweetened beverages. Of course, it also helps to keep your bedroom comfortable, cool, quiet and dark to get the best sleep possible.