The immune system explained, including how it can go wrong

The immune system is something that evolved to protect our bodies from threats that are both internal and external. Most of the time, it works flawlessly, clearing out bacteria and cancerous cells without any trouble. But sometimes, it can falter. And that’s when trouble starts. Below is an in-depth look at the immune system, from why it’s critical for health to disorders.

What is the immune system?

The immune system is like your body’s internal police force. It tracks down and destroys anything that could potentially threaten your health.

There are two parts of the immune system. That is, the non-specific and the specific.

Non-specific elements of the immune system attack all invaders, regardless of their composition. White blood cells, for instance, will try to engulf any foreign invaders they find in the blood and digest them to keep your internal organs sterile. It doesn’t matter what species they are.

The specific immune system is different. It targets particular pathways to create species-specific antigens. That’s why you don’t usually get the same disease twice. Once the body figures out a way of fighting it, it retains that information so that it can use it again.

Most diseases activate both the specific and nonspecific immune system. So, for instance, the common cold first activates white blood cells. Then, over time, specific antigens arrive and clear up the rest of the infection.

In reality, it is much more complicated than what I’ve described here, but you get the basic picture. The immune system is a complex defense network that keeps your tissues healthy.

Why it is critical for good health?

Interestingly, the immune system is also important in maintaining the health of the body’s own tissues.

As you have so many cells, the chances that some of them will malfunction is extremely high. And when they do, they can churn out dangerous chemicals, damage surrounding cells, and lead to cancer.

It makes sense, therefore, for the body to clear them out regularly. For the most part, the body uses the immune system to do so. If a cell is no longer working how it is supposed to, the body will begin “self-eating,” breaking down the cell so that it cannot do any further damage.

As people get older, though, their immune systems no longer perform this function as well. Dangerous malfunctioning cells accumulate. And that can lead to disease.

The immune system is critical for health for another reason too. It controls inflammation as a response to an infection or irritation.

You may have heard the term “inflammation” while reading health blogs. Swelling, redness, and heat around a wound are all good examples of the process in action. The body uses inflammation to change the shape of tissue to fight off infection and assist recovery.

When you cut yourself, this type of inflammation is good for you. But sometimes inflammation levels can remain high, even when you’re neither injured nor sick. That can ultimately damage the tissues and organs in your body.

The body produces compounds called cytokines to determine the level of inflammation. In the short term, these chemicals are good because they protect you from external threats.

But if these chemicals regularly stay at a high level, they can do damage. In fact, they seem to be central to the aging process itself, which is why many scientists have coined the term “inflammaging.” The older people get, the increasingly overactive their immune systems become.

Overactive immune systems

There are all sorts of reasons for overactive immune systems. One of the main contributing factors is allergic reactions. Sometimes the immune system can mistake an otherwise harmless particle in the air for a serious threat to your health. That can produce an inflammatory response.

People with allergies know what happens when their immune systems become overstimulated. They develop all the hallmarks of an infection, such as itchy eyes, runny nose, sneezing, coughing, and even fever.

The weird thing about this process is that the particle, whatever it is, isn’t actually a threat to the body. It’s just that the immune system thinks it is and goes into overdrive mistakenly.

The type of allergies people get depends on where they live. You can check out this map of allergens tested in your region to learn more. Particles get into the air and then travel into the respiratory tract, provoking the immune system to respond.

In many cases, the symptoms are unpleasant but not serious. However, in some cases, such as anaphylaxis, they can be life-threatening.

Conditions that arise from an overactive immune system

If you read a lot of science articles, you might have come across the term “auto-immune” disease.

The concept is quite simple. It’s the idea that the immune system itself creates disease by being overly active or vigilant.

Think about when people get organ transplants. If the immune system was a rational entity, it wouldn’t attack organs because they are vital for the survival of the body as a whole. But because it relies on chemical messaging, it isn’t always able to distinguish friend from foe. That’s why so many transplant patients have to go on immune suppression drugs.

This, however, isn’t the only example of conditions that arise from an overactive immune system. There are many other chronic diseases that arise via similar mechanisms.

Take rheumatoid arthritis, for instance. In this disease, the body mistakes a protein in the cartilage in your joints for a foreign invader and starts attacking it, causing swelling, pain, and joint damage over time.

Multiple sclerosis is another good example of an autoimmune issue. Here the body starts destroying the fatty layer that protects nerve cells, damaging them over time.

Celiac disease is also an autoimmune disease. Here, the body mistakes gluten, a protein found in wheat, for a dangerous invader, causing an inflammatory response in the gut.

There are plenty of other examples out there of dangerous autoimmune diseases. The ones mentioned above are some of the most common ones.

What causes autoimmune disease?

The causes of autoimmune disease are specific to the illness.

Evidence, for instance, suggests that a type of bacteria in the bladder might confuse the immune system in rheumatoid arthritis patients.

However, many autoimmune diseases appear to result from high levels of stress. It turns out that the stress hormone, cortisol, can temporarily deactivate a person’s immune response, making them more susceptible to infection.

The body does this to conserve energy in stressful situations. But if levels remain elevated for a long time, it provides an opportunity for pathogens to grow and cause serious disease.

Cortisol can also have other harmful effects on the body. Evidence, for instance, suggests that it can affect both digestion and metabolism, putting people at higher risk of chronic disease. Part of this effect could result from a less active immune system.

Strategies to improve your immune system

So what, if anything, can you do to improve your immune system? Perhaps the best strategy is to find ways to reduce the levels of inflammation and stress in your body.

Improving your eating habits is one option. Research shows that processed and animal foods are much more likely to create the conditions that lead to autoimmune issues than plant foods. You can also take a test to find out which allergies you have already so you can avoid certain foods.

Another strategy is to improve how you manage stress. Being stressed out all of the time has real and lasting effects on the body, many of which you want to avoid.

By getting more sleep, improving your diet, and reducing your workload, you may be able to protect your immune system and keep it healthier for longer.

It’s worth pointing out that some people have a genetic predisposition to immune dysfunction. But, as always, genes are not destiny. Usually, you need certain environmental factors to be present as well before the system as a whole goes wrong.

Proper oral hygiene is another strategy that you can use to improve your immune system. It turns out that bacteria in the mouth can ramp up your immune response. Elevated levels of white blood cells can damage tissues elsewhere in your body and even lead to heart disease.

The good news is that you can easily protect your teeth. Brushing and flossing help, but the real trick is to avoid sugar and “sticky” foods that contain micronized particles.

When possible, eat foods in the form that they came out of the ground. Avoid refined grains or heavily processed foods as these provide the perfect environment for bacteria to become established.

Another way to potentially boost your immune system is by eating anti-inflammatory plants. These appear to work in the body in sophisticated ways. They seem to be able to tamp down unwanted inflammation while allowing the body to create inflammation when it needs it.

Good examples of foods to consider adding to your diet include walnuts, parsley, berries of all types, nuts (as long as you’re not allergic), bell peppers, and greens. These help to regulate your immune response and prevent it from playing up.

Of course, booking an appointment with your doctor is a must if you feel something is wrong with your body, whether it’s related to the immune system or not. This professional can advise you on what is best for your unique body and refer you to a specialist if needed.