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How to Use Your Immune System to Stay Healthy

By Mary Anne Dunkin
WebMD Feature

Do you seem to catch cold after cold, while your friends sail through winter unscathed? Maybe you need to think about strengthening your immune system.

You may pay more attention to the health of your immune system during the winter, when colds and flu surround you. But the truth is, your immune system has to work hard all through the year, whether it’s offering protection from a flu virus or an infection that could happen any time.

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“We are endowed with a great immune system that has been designed evolutionarily to keep us healthy,” says Bruce Polsky, MD, interim chairman department of medicine and chief division of infectious disease at St. Luke’s-Roosevelt Hospital Center in New York City.  

How the Immune System Works

The immune system is your body’s natural defense system. It’s an intricate network of cells, tissues, and organs that band together to defend your body against invaders. Those invaders can include bacteria, viruses, parasites, even a fungus, all with the potential to make us sick. They are everywhere – in our homes, offices, and backyards. A healthy immune system protects us by first creating a barrier that stops those invaders, or antigens, from entering the body. And if one slips by the barrier, the immune system produces white blood cells, and other chemicals and proteins that attack and destroy these foreign substances. They try to find the antigen and get rid of it before it can reproduce. Failing that, the immune system revs up even more to destroy the invaders as they multiply.

The immune system can recognize millions of different antigens. And it can produce what it needs to eradicate nearly all of them. When it’s working properly, this elaborate defense system can keep health problems ranging from cancer to the common cold at bay.

When the Immune System Breaks Down

Sometimes the immune system makes a mistake and identifies a substance as being harmful when it’s not – think pollen or pet dander. When the immune system revs up to fight these “invaders,” you have an allergic reaction.

Nor can your body fight off every invader. Despite its marvels, the immune system does break down from time to time, says Polsky. “There are diseases that we have no control over, but lifestyle aspects are very, very important,” he tells WebMD.

Not eating healthily, being sedentary, not getting enough sleep, and being under chronic stress can all contribute to a weak immune system. When your immune system is depleted, bacteria, viruses, or toxins can overwhelm the body. The result? You get sick.

Building Healthy Immunity

There’s no single pill or supplement you can take to boost your immune system. Instead, adopting these healthy living habits can help improve your immunity for a lifetime.  

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