How the Immune System Works to Fight Disease

April 24, 2020

Think about your immune system as being an army, and it’s fighting infection.

Mikhail Varshavski

The immune system is essential to keeping us alive. Without it, the body would have no defense against viruses, bacteria, parasites, and other harmful agents. When everything is working as it should in the immune system, you won’t even notice it. Yet, when it becomes weakened or can’t fight especially powerful germs, that’s when things go awry.

Luckily, there are many things you can do to boost your immune system. But first, it’s important to understand how all the elements of the immune system work together.

What Is Your Immune System?

There are a few key players in the immune system which work to keep us healthy. These include different cells, organs, tissues, and proteins. Each of the following has an important role in fighting off disease:

  • Skin: Your skin is the primary line of defense against harmful invaders. Skin cells can create special proteins to fight off microbes, and each layer of skin uses unique immune cells to defend against disease.
  • Bone marrow: Within the bone marrow are stem cells. These powerful cells can transform into almost any other cell type. Some become immune cells, which are the body’s next line of defense against infection after the skin.
  • Bloodstream: The bloodstream is the key method of transportation for immune cells. They use the blood to travel throughout the body and look out for any signs of foreign invaders. Doctors also use a patient’s blood to look for changes in white blood cell levels.
  • Thymus: Located in the upper chest, the thymus is a small organ where certain immune cells mature.
  • Lymphatic system: The lymphatic system allows the immune system tissues and bloodstream to communicate. It’s made up of organs, vessels, and tissue. Immune cells meet in the lymph nodes, which are located in several places throughout the body. There, immune cells share information to activate the appropriate immune response.
  • Spleen: The spleen enriches immune cells. If harmful pathogens are present in the blood, immune cells will activate in this key organ, which is located behind the stomach.
  • Mucosal tissue: Within the respiratory tract and intestines, there are specialized immune hubs. There, immune cells patrol and take samples to look for any pathogens. [1]

How Does the Immune System Activate to Fight Disease?

Antibody Immunoglobulin made by the immune system

The main roles of the immune system:

  • Fights the germs that cause disease, including viruses, bacteria, and parasites.
  • Responds to harmful environmental substances.
  • Fights any changes in the body that cause disease.

When the body encounters something that it doesn’t recognize, the immune system responds. These foreign substances are called antigens. Viruses, bacteria, and fungi all have antigens. The first time the body comes into contact with a special process, it begins to fight it. The innate portion of the immune system uses cells such as natural killer cells to attack the invader. Many components of the immune system contain these cells. [2]

Next, the adaptive portion of the immune system creates antibodies. This allows the body to fight any germs which it has already encountered any time they reappear. The same response kicks in when you get a vaccine. Your body receives a small dose of the illness so it can create antibodies.

Naturally, the new illnesses for which your body doesn’t yet have antibodies pose the greatest threat. Yet, there are still ways to keep your immune system healthy so it can work its best.

What Can You Do to Strengthen Your Immune System?

From taking the best possible care of your body to maintaining good hygiene, here are a few simple things you can do to give your immune system the best chance of fighting off disease.

  • Eat well. Like any system in your body, the immune system needs plenty of nutrients to perform its best. Get plenty of lean protein, vegetables, and healthy fats in your diet.
  • Follow a regular sleep schedule. If you don’t get enough sleep, your body’s white blood cell production can suffer. Try to get at least seven hours of quality sleep each night. [3]
  • Exercise. Be sure to get moderate physical activity on most days of the week. This reduces your risk of catching viruses. [4] Avoid too much strenuous exercise if you’re concerned about your immune system, as exhausting the body could make it more prone to infection. [5]
  • Reduce stress. Find healthy coping mechanisms to handle stress. Consider meditating, journaling, practicing yoga, or another outlet to address any worries.
  • Disinfect your spaces. Wipe down surfaces such as doorknobs, countertops, light switches, and other key areas.
  • Maintain strong hygiene. Wash your hands often for at least 20 seconds. Avoid touching your face and stay away from anyone who may be ill.

In Conclusion – Immune Systems are the Body’s Defense Against Disease

The threat of new illnesses can be overwhelming. Yet, your body already has nature’s best defense against disease, the immune system. Plus, there’s still plenty you can do to stay in control of your health. By following the simple tips above, you can give your body the best chance of staying healthy. Here at Cenegenics®, we prime the immune system for peak performance by taking a highly scientific approach to fine-tuning the body at the cellular level.

Key Resources

This guide was produced with contributions from the following key resources:

The Textbook of Age Management Medicine V1 for nutrition, mastering healthy aging, exercise and hormone replacement therapy

The Cenegenics Education and Research Foundation  

The Textbook of Age Management Medicine Volume 1: Mastering Healthy Aging Nutrition, Exercise and Hormone Replacement Therapy

Click to purchase

The Textbook of Age Management Medicine V2 for nutrition, mastering healthy aging, exercise and hormone replacement therapy

The Cenegenics Education and Research Foundation  

The Textbook of Age Management Medicine Volume 2: Mastering Healthy Aging Nutrition, Exercise, and Hormone Replacement Therapy

Click to purchase

Textbook Authors:

Jeffrey Park Leake, M.D., CPT

Dr. Jeffrey Park Leake is a Partner and Director of Education at Cenegenics Elite Health specializing in age management and wellness. Having trained hundreds of physicians worldwide, Dr. Leake is also the Director of Education for the Clinical Strategies for Healthy Aging course at AMM Educational Foundation.

Todd David Greenberg, M.D., CSCS

Dr. Todd Greenberg is a practicing physician with a broad range of expertise, including wellness, exercise, sports injuries, and MRI of sports injuries. He is a Radiology Clinical Associate Professor at the University of Washington.

Additional Resources

Understanding Preventive Care: Age Management vs Anti-Aging

Youth is a Feeling – Not a Number

Why Can’t I Sleep? – Clinical Explanations

The Main Causes of High Cholesterol | Road Map to a Heart Attack

The Role of Vitamins and Minerals as Micronutrients

Cenegenics Elite Health Program: Why You Should Consider Age Management Your Next Investment

Causes and Symptoms of Anxiety Disorders

What Is Age Management Medicine?


[1] Overview of the Immune System. National Institute of Allergy and Infectious Diseases. Derived from: https://www.niaid.nih.gov/research/immune-system-overview

[2] How does the immune system work? InformedHealth.org. Derived from:  https://www.ncbi.nlm.nih.gov/books/NBK279364/

[3] Sleep deprivation effect on the immune system mirrors physical stress. National Sleep Foundation. Derived from: https://www.sleepfoundation.org/articles/sleep-deprivation-effect-immune-system-mirrors-physical-stress

[4] Evaluation of immune response after moderate and overtraining exercise in wistar rat. Zahra Gholamnezhad, Abolfazl Khajavi Rad, Mohammad Hossein Boskabady, Mahmoud Hosseini, and Mojtaba Sankian. National Institutes of Health. Derived from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938879/

[5] The immune system and overtraining in athletes: clinical implications. AC Hackney and Koltun KJ. National Institute of Health. Derived from: https://www.ncbi.nlm.nih.gov/pubmed/23540172

Contributor: Rudy Inaba Vice President of Health Performance

Rudy Inaba is Cenegenics’ Vice President of Health Performance. He is a recognized fitness and sports nutrition consultant with nearly 15 years of experience in clinical exercise physiology and lifestyle management. After pursuing his Master of Science in Clinical Exercise Physiology at the University of Nevada Las Vegas, Rudy joined Cenegenics where he leads 19 clinical locations nationwide in their advancements in kinesiology, nutritional biochemistry, and their analyses of industry research & market trending.