How Healthy Is Your Immune System?

Get the 101 on this finely tuned machine and make sure yours is running at full capacity.

October 23, 2014

A speedy recovery happens thanks to the hard work of your immune system. Your body is constantly exposed to microbes—it's actually home to trillions of bacteria. In fact, there are more microbes in your body than your own cells, and yet you avoid getting any kind of infectious illness from these microbes inside you. 

An amazing collaboration between your cells and the "magic molecules" they produce keeps you protected from both what's inside you and what can invade from the outside world. How come you don't catch everything that's going around? The short answer: your amazing immune system.


What exactly is the immune system, and where is it located? Turns out, it's not just parked in one place. It has outposts all over your body. It's really a protection or guardian network, since the immune cells connect with every other system and part of your body. 

This network encompasses your skin, bone marrow, organs like the thymus and spleen, hormones and molecular messengers, as well as your brain, muscles, and even your mind.

More: 12 Surprising Immune System Killers

This network is a master of communication, and it consists of four main parts:

• Physical barriers, such as your skin, saliva, tears, and stomach acid
• White blood cells, including phagocytes and lymphocytes
• Organs where immune cells are produced (thymus and bone marrow) and where they do most of their work (lymph nodes and spleen)
• Molecules, including antibodies and cytokines.

Your immune cells don't operate alone, though; they're influenced by what you think, what you do, and the choices you make every day. Chronic stress, depression, poor sleep, or a steady diet of junk food can keep them from working at their best. 

But there's good news: You can improve and rebalance your immune functions with stress-reduction strategies; healthy, nutritious food; the right supplements; a good night's sleep; and healthy, supportive relationships. And here's a bonus: Laughter and love also strengthen immunity and boost your mood.

More: Practicing Mindfulness May Boost Your Immunity

Although the immune system is viewed as one system, its cells, organs, and chemicals are distributed throughout your body and are in constant communication. Sometimes called a roving sensory network, your immune cells patrol your whole body. 


When they're working well, you don't even know they're there. But when they're overwhelmed by an invading army of germs or get confused about what's safe and what's not, you may find yourself with infections, allergies, or an autoimmune disease.

Adapted From Ultimate Immunity