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Sleep And Immunity: How Sleep Affects Your Immune System

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    Last Updated
    July 26, 2022
    min read

    When you get enough deep sleep, you feel rested and energized for the day. But did you know that healthy sleep also leads to a healthy body? 

    Keep reading to learn more about the effects of sleep deprivation on your immune system, and why you should develop a consistent sleep schedule.

    How Does Our Immune System Work?

    The immune system works through a series of interconnected networks that protect you from viral infections and bacterial infections. These networks are generally split into two categories: adaptive and innate immunity:

    • Adaptive immunity is also known as acquired immunity. It's built from defenses your body has gotten over time. 
    • Innate immunity is the immunity that you're born with. It’s the first line of defense against infection.

    What Is A Balanced Immune Response?

    When it's operating optimally, your immune system balances protecting your body and attacking potential threats like bacteria. If you're injured or get sick, it activates your immune system. Your immune system can respond in a number of ways to fight off these threats, such as inflammation, fever, pain, or fatigue.

    While your immune system needs to be responsive and strong enough to combat infections, it should also be regulated so your body isn't constantly on high alert. It should be able to distinguish between actual threats and harmless cells and substances. When the latter happens, this overreaction from your body may lead to auto-immune diseases or allergies.

    How Does Sleep Affect The Immune System?

    Sleep can boost your immunity, response to vaccines, and ability to fight off allergies. Let’s break each of these down below:

    Innate And Adaptive Immunity

    Research suggests that sleep helps both innate and adaptive immune health. During nightly sleep, parts of the immune system have increased activity. For example, inflammatory cytokines are cells that are produced when innate immune defenses are activated. Studies have shown that their production is heavily affected by our sleep cycles and the body's circadian rhythm a.k.a. its internal 24-hour clock.

    Insufficient sleep reduces the number of deep sleep cycles that we have. Deep sleep has been scientifically found to influence the body's physical repairs and immune system memory. This might explain the growing link between sleep disorders and a weaker immune response.


    Sleep regulation is said to have a strong impact on vaccine efficacy. Vaccines introduce antigens that are weakened or deactivated into the body. This triggers the immune system and teaches it to recognize the antigen to fight it off, giving the body better defenses.

    Studies have shown that when people have inadequate sleep before vaccination for swine flu (a.k.a. H1N1) and hepatitis, their immune response will be weakened. This reduces vaccine efficacy and might even require a second vaccine shot.

    While some studies demonstrate the impact of sleep deprivation on vaccines, others show that even just getting less than 7 hours of sleep can lower your immune response. This may be because a lack of sleep time (specifically deep sleep) affects the development of the immune system's memory, reducing protection despite the vaccine.


    Allergies happen when our immune systems have an overreaction to something that is not normally harmful, such as chicken or fruit. Research has shown a strong link between bad sleep and increased severity of allergic reactions. 

    A study recently found that lack of sleep can make people with peanut allergies more likely to have an allergy attack, lowering the amount of peanut exposure they need to have an attack by 45%.

    Can Sleep Deprivation Make You Sick?

    Yes, sleep deprivation makes it easier for you to get sick. One of the common consequences of sleep deprivation is an increased risk of infection. People who sleep less than the recommended minimum 7 hours of sleep are more likely to catch a common cold or the flu.

    Studies have also found that bad sleep can affect your recovery from illnesses or make you develop severe health issues over time. Poor sleep has been linked to many long-term health issues, possibly because of the bad effects of sleep deprivation on the immune system.

    For example, people who have healthy sleep patterns have their bodily inflammation go down to normal levels at night before waking in the morning. But if you don't sleep enough, this inflammation may persist. This consistent inflammation can contribute to developing numerous diseases, such as cardiovascular illnesses, diabetes, and even depression.

    Don't be fooled by the fact that you may still get through your day despite a lack of sleep. Studies show that while you may feel like you can manage on limited sleep, your immune system doesn't adjust to this poor sleep schedule. Low-level inflammation may persist and become chronic, leading to the health issues mentioned above.

    How Does The Immune System Affect Sleep?

    While sleep affects one's immune function, the immune system, in turn, also affects sleep in different ways. For example, an infection can trigger your immune system and make you feel lethargic and sleepy. This explains why people who are sick spend a lot of time in bed resting or sleeping.

    The way we sleep also shifts when we're fighting off an illness, changing our sleep duration in certain sleep stages. Our immune responses induce longer hours in deep sleep, which slows down our body's processes and gives us more energy to combat sickness.

    Researchers are still studying the relationship between sleep and our antibody production and response. These are just some of the effects that show a strong link between them and how our immune system makes use of sleep for immune activation.

    4 Sleep Habits To Strengthen Immunity

    Now that you know more about the relationship between sleep and a strong immune system, here are four things you can do to get restful sleep. These tips will help you develop a normal sleep and wake schedule!

    Change The Sleeping Environment

    Having trouble getting those forty winks in? Reduce the chances of sleep disturbance interrupting your cycle by changing your environment:

    • Put away distractions like your mobile phone and laptop so you won't be tempted to scroll the night away.
    • Keep a glass of water nearby so you can quickly quench your thirst and go back to sleep instead of getting up. 
    • Keep your work and sleep areas as separate as you can so you don't get tempted to check on updates. 

    By removing outside stimuli and distractions, you can focus on getting more sleep time.

    Good Sleep Hygiene

    Sleep hygiene habits help you get 7-9 hours of proper sleep at night. Develop these sleep regulation routines to let your body know it's time to rest, allowing you to eventually settle into a consistent sleep schedule.

    Good sleep hygiene habits include having set times for sleeping and waking, reducing screen time, and setting a deadline for caffeine and alcohol consumption before bed.

    Get A Good Mattress And Pillow

    An uncomfortable bed can make for poor sleep quality. Find a high-quality mattress and pillow that will support your body and prevent your nightly sleep from being disturbed. 

    People with back problems should look into getting lumbar mattresses. Memory foam pillows and mattresses are also highly praised by restless sleepers for improving posture and promoting high-quality sleep.

    Relaxing Exercises Before Bed

    Some exercises or relaxation techniques can destress your mind and body. When done before bed, these can reduce your sleep loss and give you a deeper sleep. Numerous studies have shown that methods like tai chi or yoga can improve sleep and enhance immune function.

    Frequently Asked Questions On Sleep And Immunity

    Can too much sleep weaken your immune system?

    While a few extra hours is okay on the weekends, oversleeping can have negative effects on your immune health. Sleeping more than 9 hours a night is often the result of catching up on a lack of sleep. It can also be caused by inadequate sleep quality, which could result in needing more sleep hours to feel rested.

    Longer sleep hours have been linked to serious physical and mental health problems, such as depression, cognitive impairment, and inflammatory diseases. It also increases your risk of having a stroke, coronary heart disease, or a heart attack. 

    How can I strengthen my immune system?

    Your immune system can be strengthened by good practices like:

    • Getting vaccinations for protection against diseases such as chickenpox and polio
    • Eating a healthy, balanced diet
    • Staying physically active every day
    • Regularly washing your hands
    • Getting a good night's sleep

    Does sleeping improve immunity?

    Yes, sleeping improves immunity. Getting adequate sleep every night can improve cell memory and build defenses against viral and bacterial infections. It also reduces the likelihood of developing serious health issues such as inflammatory diseases.

    About the authors

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