You probably know that your body’s immune systemExternal Site works hard to fight off germs and other invaders that can cause everything from a mild cold to a more serious illness. But, that’s probably the extent of your knowledge — unless you’ve studied it in school, of course.

Despite being a mystery to most people, the immune system plays an important role in the human body. It’s one of the most complex systems in your body, second to only your nervous system.The immune system is made up of tissues, cells and organs. It includes your white blood cells, bone marrow, lymph nodes, spleen, digestive system, tonsils and even your skin.

Knowing how your immune system does its job and what you can do to keep it in tip-top shape is just another way you can take care of yourself. Try these five ways to give your immune system a healthy boost:

1. Wash your hands

   One of the ways you can help your immune system is by giving it less to deal with in the first place. Washing your hands throughout the day, especially after you’ve been in a public place, can help reduce your contact with germs. When your immune system has fewer germs to fight, you're less likely to get sick.

2. Eat healthy foods

   Another way to support your immune systemExternal Site is by eating a wide variety of foods that are high in nutrients. Vitamins and minerals found in fruits, vegetables, whole grains, beans, and nuts can help keep your immune system running smoothly, while antioxidants can help prevent damage to your immune cells. If you find it challenging to keep up with your daily intake of fruits and vegetables, ask your doctor if you should add a multivitamin to your diet.

3. Stay active

   You probably already know that getting regular physical activity is good for your health — it strengthens your muscles, can help you maintain a healthy weight, and produces endorphins that can boost your mood. But, working out can also help your immune system in a number of waysExternal Site, according to WebMD®.

   Regular exercise helps your bloodstream work more efficiently. This helps antibodies and white blood cells spring into action and get to where they need to be quicker when fighting germs. Following the recommended guidelines for physical activityExternal Site also can help prevent body fat from building up, which can affect your immune system as you age.

4. Manage your stress

   Do you ever wonder why college students tend to get sick at the end of the semester when they’re studying for final exams? Or, why you find yourself catching cold after cold during a busy time at work? The answer could be chronic stress. When we’re burning the candle at both ends, we’re often not taking good care of our bodies — like eating well or getting enough sleep. Though scientists continue to studyExternal Site the relationship between immunity and stress, reducing sources of stress will boost your physical and mental health.

5. Get enough sleep

   Sleep is incredibly important for your health — but not everyone is getting enough of it. According to the Centers for Disease Control and Prevention, getting less than five hours of sleep each night can double your risk of heart disease, heart attack, and/or stroke.

   Sleep deprivation can hamper your immune system, too. Without enough restExternal Site, your body will make less cytokinesExternal Site and other important immune cells that help target infections and destroy viruses — leaving you more vulnerable to colds and other illnesses.