Your body heals and regenerates while you sleep, making adequate sleep critical for a healthy immune response, Lin says. More specifically, studies have found that sleep is a time when your body regulates key immune cells and molecules like cytokines (a type of protein that can either fight or promote inflammation) and T cells (a type of white blood cell that regulates immune response).
“Getting adequate rest may strengthen your body’s natural immunity,” Cherian says. When you don’t get enough sleep, your immune system may not function as well, making it less able to defend your body against harmful invaders and making you more likely to get sick.
Research suggests healthy adults with insomnia are at an increased risk of infection compared with healthy adults without the sleep condition. Sleep deprivation also elevates the levels of our stress hormone cortisol, which, of course, is also not good for immune function, Lin says. “Our immune system wears down as a result, and we tend to have [fewer] reserves to fight off or recover from illness.”
It’s recommended that adults get between 7 and 9 hours of sleep per night for optimal health. To get quality shut-eye, prioritize good sleep hygiene: Turn off your electronics at least two to three hours before bed, and avoid violent or stressful books or conversations, Lin says.
4. Strive for Mental Balance
Research shows that long-term stress may lead to chronically elevated cortisol levels, which can essentially force your immune system to shut down. While this “shutdown” response is beneficial in the short-term, keeping us healthy until stressful events are over, it’s not helpful for our long-term ability to fight bacteria and viruses.
This is why it’s important to incorporate stress-reduction techniques; the key is to find what works for you. “I like to give my patients options,” says Ben Kaplan, MD, an internal medicine physician at Orlando Health Medical Group Internal Medicine in Florida. He recommends meditation (apps like Headspace and Calm can help), journaling, and any activity that you enjoy, such as fishing, playing golf, or drawing.
Similarly, opportunities to laugh may reduce overall stress, making you less susceptible to illness in the long run, Cherian notes. And don’t underestimate the power of nurturing your relationships: Studies have found that social connections may lead to a greater sense of support, thereby reducing stress hormone levels.
5. Stay Current on Vaccinations
Getting regular vaccinations can help support your immune system, bolstering your body’s natural defenses against harmful viruses and bacteria. Without vaccination, it can take your immune system seven to 14 days to organize and launch a full-scale attack against disease-causing pathogens.
“And unfortunately, depending on how much you’re exposed to and whether you’re a healthy young person or a more senior person whose immune response is waning, the end of those 14 days can result in you getting infected or staying healthy,” says LJ Tan, PhD, the chief strategy officer for Immunize.org in Saint Paul, Minnesota.
If you get sick, your immune system will then help bring things back under control so you can recover. But vaccines may shorten that two-week waiting period by letting your immune system engage with a piece of the virus or bacteria.
“We introduce it to your immune system in a very controlled manner, such that it cannot cause infection,” Dr. Tan says. “Once your immune system has gone through this initial stimulation, it generates memory immune cells that have seen the enemy and are ready to go when they see the enemy again.” The official term for this phenomenon is the “anamnestic response.”
In general, memory immune cells eventually die off, and protective antibodies decline over time. With some infectious diseases, you have to reintroduce your body to pathogens with regular vaccination, such as with a booster, to keep your immune system responsive. How often you need a booster will vary depending on the pathogen — for example, the U.S. Food and Drug Administration (FDA) recommends a flu shot every year — so be sure to touch base with your physician.
While vaccines are safe and effective for most people, Tan advises some individuals to consult their healthcare teams before vaccination. That includes people who are immunocompromised because of treatments like chemotherapy and anyone with a history of allergic reactions to vaccines.
6. Make Conscious Hygiene Part of Your Routine
Personal hygiene may not directly improve immune system health, but basic habits like washing your hands, using hand sanitizer, wearing a mask, and staying home when you do get sick can prevent the spread of germs.
“We have this incredible immune system that helps us stay healthy, but if we can avoid challenging that immune system, we’re going to stay healthier in general,” Tan says. “This way, you can also hopefully reduce your exposure to pathogens that we don’t have vaccines for.”
Wash or sanitize your hands after using the bathroom, before and after shaking hands with others, after coughing or sneezing, and after making contact with high-touch surfaces like countertops and door handles. “I carry a bottle of hand sanitizer with me everywhere, simply because I’m an infection control expert and I know what the benefits are,” Tan says.
Research shows that hand sanitizers containing 60 percent alcohol can be just as effective for killing germs as washing your hands with soap and water. But, of course, handwashing is the gold standard for preventing the spread of germs.
Cover your nose and mouth when you cough or sneeze so you don’t spread your droplets to people around you. Stay home if you do get sick to prevent spreading your germs to others.
7. Avoid Toxins Like Alcohol and Cigarettes
Try to limit or avoid alcohol and quit smoking if it’s a current habit, to support your immune system.
High alcohol consumption is associated with a range of negative health effects, including lowered immune function. When you drink to excess, your body is too busy trying to detoxify your system to bother with normal immune system function, Kaplan explains.
Studies show that chronic heavy alcohol use can lower the levels of immune cells in your body. People who drink heavily also face a greater likelihood of pneumonia, acute respiratory syndrome, alcoholic liver disease, and certain cancers. If you drink occasionally, limit your alcohol consumption to one to two drinks per day.
Like alcohol, cigarette smoking can affect immune health. “Anything that’s a toxin can compromise your immune system,” Kaplan says. Specifically, the chemicals released by cigarette smoke can interfere with the growth and function of immune cells, like cytokines, T cells, and B cells.
Smoking also worsens viral and bacterial infections (especially those of the lungs, like pneumonia, flu, and tuberculosis) and postsurgical infections.
“Don’t smoke,” Lin says. And avoid secondhand smoke whenever possible. If you currently smoke, there are many resources available to help you kick your habit, including counseling, nicotine replacement products, prescription non-nicotine medications, and behavioral therapy.
8. Keep Symptoms of Chronic Conditions Well Managed
Chronic conditions like asthma, heart disease, and diabetes can affect the immune system and increase your risk of infections.
For example, when people with type 2 diabetes don’t manage their blood sugar properly, a chronic, low-grade inflammatory response can ensue that weakens the body’s defense system. Similarly, people with asthma are more susceptible to catching the flu and often experience worse flu and asthma symptoms as a result of the infection.
Properly managing your chronic condition can help free up reserves for your body to fight off infection, Lin says. So, be sure to stay on top of any medications, doctor visits, and healthy habits that keep your symptoms at bay. Your immune system will thank you.
The Takeaway
Your immune system is a complex system of skin cells, blood, bone marrow, tissues, and organs that help your body fight off disease-causing pathogens. When it’s not working properly, however, you might be more prone to illness and infection.
Keeping your immune system healthy involves a combination of lifestyle and medical changes to improve your overall health. This means eating a balanced diet, getting enough sleep, managing stress, getting daily exercise, and avoiding toxins like cigarette smoke and heavy alcohol consumption.
Habits like washing your hands, using hand sanitizer, wearing a mask, and staying updated on vaccinations can help protect your immune system against infection and illness.
If you have an underlying chronic health condition, visit your doctor regularly and manage symptoms to improve your body’s immune function.
