From keeping germs out of your body to healing a cut or bruise, your immune system works hard to keep you healthy. But what happens when you feel like your immune system isn’t at its best? Can you do anything to change that?

The good news is there’s a lot you can do to strengthen your immune system. We’ll explain what the immune system does, why it’s so important and ways you can boost it with healthy foods, lifestyle changes, and (at times) vitamins and supplements.

What is the immune system?

Your immune system is your body’s natural defense against infection. It’s made up of a large network of organs, cells, proteins and chemicals that protect your body from bacteria, viruses, toxins and other invaders. When the immune system senses these invaders, it will unleash an immune response to protect your body from unwanted substances.

Parts of the immune system

Your immune system is broken up into two parts – the innate immune system that you’re born with and the adaptive immune system that develops over time as your body is exposed to different things.

These two parts of the immune system are comprised of different organs, cells and proteins that work together to protect your body, including:

  • Adenoids
  • Antibodies
  • Bone marrow
  • Lymph nodes
  • Lymphatic vessels
  • Mucus membranes
  • Peyer patches
  • Skin
  • Spleen
  • Thymus
  • Tonsils
  • White blood cells

Why a strong immune system is important

A healthy immune system can keep you from getting sick, help you fight off an infection if you do get sick, and is vital for your overall health. Your immune system learns about the germs you’ve been exposed to and develops antibodies. These antibodies can protect your body from the same kinds of germs in the future so you’re less likely to get sick, or you’ll experience milder symptoms if you do get sick.

When your immune system isn’t working properly, it can launch an unnecessary attack when no germs are present or fail to stop an attack after the invading germs have been eliminated. Autoimmune diseases, allergies and their corresponding symptoms are some examples of how these unwelcome attacks can affect the body.

Signs of a strong immune system

Everyone has a unique experience when it comes to their body and overall health, but there are some clues that can distinguish those with a strong immune system from others. People with a strong immune system are more likely to recover quickly from an injury or illness, feel less fatigue and have good gut health.

Signs of a weak immune system

People at risk of having a weak immune system are often older or suffer from chronic conditions like heart disease, diabetes or cancer. These people can be immunocompromised – meaning their body can’t fight off invading germs very well. People with a weakened immune system are more likely to experience conditions like anemia, autoimmune disorders and higher frequency of infections.

There’s a lot you can do to keep your immune system strong and working its best. From the food you eat to your daily routine, many elements can positively impact your immune system. Explore ways to enhance your immune system naturally or with vitamins that contain immune system boosters.

Natural, habit-based ways to boost your immune system

Making some simple changes in behavior and forming new habits can help you to naturally boost your immune system, including:

  • Getting enough sleep – While we sleep, our bodies can take the energy that is normally used to keep us going throughout the day and devote it to the immune system. During this time, the immune system takes that energy and bolsters its defenses, so it can be ready the next time we need it.
  • Exercising regularly – We know exercise can keep us healthy, but recent research has shown that regular movement sends more white blood cells (the immune system’s soldiers) patrolling around the body, increasing the likelihood that they will spot and respond to infection or invading viruses sooner.
  • Washing your hands frequently and practicing good hygiene – We often don’t realize how much we touch shared surfaces throughout the day. Door handles, stairway railings and public transit handrails can all leave us with germs on our hands. Then we touch our faces, our phones, or our food as we eat, and if we haven’t washed our hands, those germs are now significantly more likely to infect us.
  • Maintaining a healthy weight – Being overweight means many parts of the body have to work harder to function, and this includes the immune system. According to the Centers for Disease Control and Prevention, obesity causes diminished immune system responses, and can even decrease the potency of many vaccines in the body.
  • Managing stress – When you feel stressed out, your body produces a hormone called cortisol. In small amounts, cortisol actually helps reduce inflammation, among other useful benefits. But, over time, sustained levels of cortisol start to increase harmful inflammation and decrease our supply of white blood cells.
  • Avoiding cigarettes and other tobacco products – Smoking introduces toxic chemicals into the body that can disrupt the normal function of the immune system and increase your risk of developing an autoimmune disease.
  • Drinking alcohol in moderation – Excessive alcohol consumption over several years starts to slow immune system responses, leading to longer recovery time from illness or infection, and a higher likelihood of chronic and acute disease, like pneumonia, sepsis and cancer.

Strengthening your immune system through diet

Your diet can work wonders for your overall health, like giving your immune system a boost and even improving your mood. If you’re looking for natural ways to “keep the doctor away,” eat a wide variety of healthful foods, including healthy fats and foods with these nutrients:

  • Beta carotene from foods like sweet potatoes, carrots, mangoes and broccoli
  • Vitamin C-rich foods, including berries, tomatoes, bell peppers and more
  • Vitamin D that can be found in things like milk, fish and eggs
  • Zinc absorbed from foods like beef, seafood, nuts and beans
  • Probiotics in dairy products and fermented foods like sauerkraut and kimchi
  • Protein from things like milk, eggs, meat, nuts and beans

Vitamins and supplements for a healthy immune system

The best way to get the nutrients your body needs and boost immunity is through the foods you eat. If you’re eating a balanced diet, you don’t need to add vitamins or supplements into your routine to maintain a healthy immune system. But if you have dietary restrictions for health, lifestyle, religion or other reasons, vitamins and supplements may be able to step in and fill any gaps where your diet falls short. Vitamins that support a healthy immune system include:

  • Iron
  • Folic acid
  • Vitamins A, C, D and E
  • Zinc

When to see a doctor for a weak immune system

From eating healthier foods to lifestyle changes, there’s a lot you can do to strengthen your immune system, and not just right before flu season. It’s best to take care of your immune system year-round because some viruses continue to spread throughout the warmer months.

If you think you may have a weak immune system or are curious if there’s more you could be doing to boost your immune system, talking with your primary care doctor is a great place to start.