Reviewed by Minesh Khatri, MD on March 18, 2021

Kick Back and Relax


Some stress can be a good thing. It helps your body get ready for a challenge. But if it lasts too long, that’s bad news. Studies show it can weaken your body's defense system. Avoid it when you can. Make it a point to unwind and do things you enjoy.

Get Your Groove On


It doesn't just make you feel good -- it's good for you, too. One study found a link between a healthy immune system and how often you get busy. Those who made love more often had higher levels of a cold-fighting substance in their bodies.

Find a Furry Friend


There's a reason we call them "man's best friend." Dogs and other pets aren’t just good buddies. They also give us a reason to exercise and boost our health in other ways. Pet owners have lower blood pressure and cholesterol levels and healthier hearts. Dogs can help your child’s immune response and make him less likely to get allergies.

Build Your Social Network


We all know friends are important, but strong social ties can also have a big effect on your health. People with healthy relationships are likely to outlive those with poor social ties. Want to broaden your circle? Volunteer, take a class, or join a group that interests you. And nurture the bonds you already have.

Look on the Bright Side


When you think good thoughts, your body’s defenses work better. Want to stay in your happy place? Savor the things you enjoy. Look for a silver lining -- even in tough times -- and try not to dwell on the bad stuff.

Have a Laugh


A giggle or two is good for you. Not only does it make you feel better, there’s no downside. One study found that after people laughed out loud at funny videos, their immune systems worked better. But we aren’t sure yet if that means less illness in the long run.

Eat the Rainbow


Colorful fruits and vegetables are full of antioxidants. These nutrients guard against free radicals, molecules that can harm your cells. To get a wide range, go for oranges, green peppers, broccoli, kiwi, strawberries, carrots, watermelon, papaya, leafy greens, and cantaloupe.

Think About Herbs and Supplements


Some of these products can help your immune system, but we need more research to know for sure if they’re really good for you. Because they can interact with other medicines, let your doctor know if you want to try them. He can help you decide which ones are safe for you.

Move Your Body


Exercise is a simple way to rev up your defense system. It can also ease stress and make you less likely to get osteoporosis, heart disease, and certain types of cancer. You’ll get the most bang for your workout buck if you do about half an hour a day. It doesn’t have to be hard-core. Any type of movement can help: ride a bike, walk, do yoga, swim, or even play golf.

Get a Good Night's Sleep


Without it, your immune system won’t have the strength it needs to fight off illness. Most adults need about 7 to 9 hours of sleep a night. To get better shut-eye, you need to stick to a regular bedtime schedule, stay active during the day, skip caffeine and booze near bedtime, keep the bedroom cool, and give yourself time to unwind at the end of the day.

Cut Back on the Booze


Alcohol plays a major role in how we socialize and celebrate. But too much can weaken your defenses and cause you to get sick more often. How much is too much? More than two drinks a day for men and more than one for women.

Kick the Nicotine Habit


Do your immune system a favor and give up smoking. If it takes you a couple of tries before you quit for good, hang in there! Ask your doctor for advice on how to make this major life change. Stay away from secondhand smoke, too.

Wash Your Hands


Send those germs down the drain before your body ever has to fight them off. Use soap and clean, running water. Wash for at least 20 seconds. If you don't have access to soap and water, a hand sanitizer can help (unless your skin is caked with dirt and grease). Just know that it won’t remove all the germs and other bad stuff. Choose one with at least 60% alcohol.

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National Institute of Mental Health: “Fact Sheet on Stress.” 

Lindau, S. British Medical Journal, 2010

NIH News in Health: "Can Pets Help Keep You Healthy? Exploring the Human-Animal Bond."

CDC: "Health Benefits of Pets."
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American Psychological Association: “Stress Weakens the Immune System.”

News release, Association for Psychological Science.

Mental Health America: "Stay Positive."

Bennett, M. Evidence Based Complementary and Alternative Medicine, June 2009.

National Cancer Institute: "Antioxidants and Cancer Prevention."

CDC: “Managing Stress.”

Anxiety and Depression Society of America: “Exercise for Stress and Anxiety.”

Harvard Health Publications: "How to Boost Your Immune System."

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

Harvard Health Publications: "How to Boost Your Immune System."

Steps for Stress: “Avoid Alcohol and Drugs.”

National Institute on Alcohol Abuse and Alcoholism: "Beyond Hangovers: Understanding Alcohol's Impact on Your Health."

U.S. Department of Health and Human Services: “18 Ways Smoking Affects Your Health.” “How Smoking Affects the Immune System.”

CDC: "Handwashing: Clean Hands Save Lives."