We already know that sleep is important for healing and recovery. There’s a reason why plenty of sleep and rest is one of the best ways to recover from a flu and many other ailments. But does sleep also protect you from getting sick? 

That’s what we investigate in this article. We discuss the link between sleep and immunity and whether getting too little sleep can make you sicker. 

Does Sleep Affect Immunity? 

Based on the research we have so far, it is clear that sleep affects your immune response. Several studies found that people with sleep deprivation are at a higher risk of respiratory infections, common illnesses like the flu and gastroenteritis, and even herpes. 

Some studies have also found that sleep deprivation can affect the development of immunological memory after vaccination. This memory is what protects us from future infections. 

Here are some of the ways scientists think sleep quality impacts your immunity. 

1. Sleep Affects the Efficiency of T Cells 

T Cells are white blood cells that fight germs. T Cells work together with proteins called integrins to bind to cells of harmful microorganisms and kill them. 

Researchers have found that stress hormones including adrenaline and noradrenaline can prevent T cells and integrins from combining, thus inhibiting immune response. 

Stress hormones increase when you are sleep deprived. So not getting enough sleep can reduce your immunity by reducing the efficiency of T cells. Not only does this leave you more vulnerable to getting sick, it can make an illness worse since the body is not able to respond to it properly.   

2. Poor Sleep Causes/Worsens Inflammation  

Inflammation is a natural defensive reaction by our immune system against diseases. Normally, inflammation is a good thing, but only if it is short lived. 

Prolonged inflammation, what’s called chronic inflammation, is where things start going wrong. It has been linked to a host of health issues including autoimmune disorders, heart disease, high blood pressure, cancer and even mental issues like depression. 

There are plenty of things that can cause or worsen inflammation including a diet high in processed foods and a sedentary lifestyle. Sleep deprivation can also trigger or aggravate chronic inflammation. 

Essentially, it makes your immune system go haywire — it reacts when it’s not supposed to and reacts for longer than necessary. This harms healthy tissue and increases your risk of health problems.                                                                                                                                                                                                                                                                                                                                      

3. Poor Sleep Increases Risk of Obesity, Which Affects Immunity

Sustained sleep deprivation over a long period has been shown to contribute to weight gain and increase the risk of obesity. 

Obesity, in turn, can negatively affect your immune system in various ways. For example, obesity can lead to chronic inflammation, which hampers your immune system and increases your risk of various diseases. Obesity can also hamper the protective function of white blood cells.  

Several studies have found that obese patients who have been hospitalized are at a higher risk of secondary infections like sepsis and pneumonia. 

According to the CDC, one of the reasons why obese persons get sicker from Covid-19 is because they tend to have an impaired immune function.  

Does Sleep Affect Recovery and Healing?

If you are already not feeling well, not getting enough sleep can make you sicker. That’s because sleep is extremely important in recovery and healing. 

Quality sleep allows the immune system to function properly and deal with whatever’s making you sick. Sleep also allows damaged tissue to heal and recover. 

Sleep is also crucial for getting inflammation under control, an important part of recovery. 

So when your doctor orders bed rest, take it seriously. It is just as important as the meds you have been prescribed. Not getting enough sleep only keeps you sick for longer. 

How To Improve Your Sleep for Stronger Immunity 

The goal is to get 7-9 hours of sleep every night. There are people with unique genetics that allow them to get away with fewer hours of sleep without any detrimental effects. But for most of us, we need to get 7-9 hours of snooze time.  

How you achieve this depends on what’s affecting your sleep quality right now. 

If it is a sleep disorder like sleep apnea, chronic insomnia or restless leg syndrome, talk to your doctor for treatment options. 

If you find yourself sleeping at odd hours of the night or staying awake in bed long after bedtime, you probably need a healthy sleep routine. We have written a post on exactly that.  

Improving your bedroom can also help a lot with insomnia and other sleep problems. Here’s a post on how to improve your sleep environment. 

Generally, improving your lifestyles goes a long way in improving your sleep quality. Eat a healthier diet with fewer refined foods and more fiber, try to be more active during the day, reduce alcohol intake, cut out smoking, find ways to manage your stress and so on. 

Coincidentally, these changes are also great for your immunity. So you get to boost your immunity in multiple ways.  

So whether you want a stronger immunity or you are looking to quickly get over an illness, hitting the sack early is one of the best things you can do.