Your immune system includes your body's cells, tissues, and organs, which work together to fight off infections and diseases. But how much do you know about it?
When you understand everything that your immune system does for you and how everyday things affect it, you can help it keep you well.
What Does Your Immune System Do?
Your immune system fights off infections and diseases and roots out germs and other attackers that have no business in your body.
It looks out for you
For example, if you inhale a cold virus through your nose, your immune system targets that virus and either stops it in its tracks or primes you to recover. While recovery may take time, and sometimes you may need medicines to help, your immune system plays a key role in both preventing and recovering from the illness.
How Does Stress Affect the Immune System?
Do your best to tame your stress.
Chronic stress — whether from being in a difficult relationship, living with a chronic disease, or being a caregiver — can take its toll on your immune system. Over time, stress can make you more prone to illnesses. Chronic stress seems to age the immune system, studies show, making you more likely to get a cold or the flu. It also raises your risk for diabetes and heart disease.
Everyone goes through stress. What matters is how you handle it. Getting better at managing stress can help. Even something as simple as deep breathing can lessen the effects of stress. You may also try other relaxation techniques, such as:
- Meditation
- Yoga
- Other types of exercise
Counseling can make a big difference, too.
Immune System Organs
Your immune system is one of the most complex systems in your body. It's made up of tissues, cells, and organs, including:
- Tonsils
- Digestive system
- Bone marrow
- Skin
- Lymph nodes
- Spleen
- Thin skin on the inside of your nose, throat, and genitals
All of these help create or store cells that work around the clock to keep your entire body healthy, including your immune system cells.
Immune system cells
Your immune system cells are your body's white blood cells that help fight infection and disease. Most of your white blood cells form in your bone marrow, but two other types -- T cells and B cells -- are made in your lymph nodes and spleen.
Your body has five different types of white blood cells, including:
- Neutrophils: Kill bacteria and fungus
- Lymphocytes: T cells and B cells that produce antibodies and protect against viruses
- Eosinophils: Find and destroy parasites and cancer cells
- Basophils: Cause allergic responses
- Monocytes: Clean damaged cells
What Is Immunity?
You're born with a certain level of protection, or "immunity." That means your body has the ability to protect itself from infections and disease.
Think of a baby or young child who comes down with colds or earaches often. Their immune system is creating a "bank" of antibodies as they are exposed to illnesses for the first time, allowing them to fight off future attackers.
Most vaccines work in much the same way. They turn on your immune system by exposing your body to a tiny amount of a virus (usually a killed or weakened one). In response, your body makes antibodies that protect against threats such as measles, whooping cough, flu, or meningitis. Then, when you come in contact with that virus, your immune system is already primed to kick in so that you don't get sick.
Innate immunity vs. acquired immunity
There are two types of immunity, innate and acquired or adaptive. So what's the difference?
Innate immunity is considered immunity you're born with. Your innate immunity is considered the first line of defense and includes things such as tears and mucus, blood clots, stomach acids, natural killer cells, and mast cells. Your acquired or adaptive immunity is more developed over time as you're exposed to different infections, viruses, or vaccinations.
How Does Your Immune System Change Over Time?
Your immune system can become less effective as you get older. Researchers and doctors think it happens for several reasons, including:
- More inflammation as we age
- Shrinking of the thymus gland
- Antibodies becoming less effective
If you have a weakened immune system, you become more likely to get sick or get infections. And it might take longer for you to get well. Your risks of certain cancers also go up when your immune system is strained. That's because it might not spot the mutated cancerous cells as quickly, so they have more time to divide and spread.
As you get older, your immune system makes you more likely to have other age-related diseases, such as heart disease, Alzheimer's, and Parkinson’s.
Immune System Disorders
You might have heard that a flu vaccine weakens your immune system, but that’s not true. The vaccine prepares your immune system for the flu.
A flu vaccine teaches your immune system to identify that virus as a threat. Some people may still get the flu after having a flu shot, but they'll probably have a milder form of the illness. That's because antibodies made in response to the vaccine can still offer some protection.
There are, however, things that do affect your immune system.
Weak immune system
Medications like chemotherapy or infections can weaken your immune system temporarily. You can also have a weakened immune system if you smoke, drink alcohol, or don't get proper nutrition. Viral infections such as HIV/AIDS can also severely compromise your immune system because it destroys your white blood cells.
Overactive immune system
The most common type of an overreactive immune response is allergies, also called allergic rhinitis. Your body sees the allergen as an invader and attacks it, giving you a runny nose and itchy eyes. You treat allergies by avoiding what triggers them and taking medication to control symptoms. For some people, allergy shots may be an option. Over some time, usually several years, allergy shots may help your immune system get used to the allergen so that it doesn't produce the bothersome allergy symptoms. Eczema and asthma also are types of overactive immune system disorders.
Medications that can affect your immune system
- Steroids
- Chemotherapy
- Post-transplant medications (immunosuppressants)
- Medications for multiple sclerosis (MS)
- Medications for autoimmune conditions such as lupus
- Angiotensin-converting enzyme (ACE) inhibitors
Immune System Disorder Symptoms
Symptoms of an immune system problem depend on the disorder but can include any of the following:
- Fatigue
- Low-grade fever
- Unexplained weight loss
- Night sweats
- Itchy skin or rash
- Sore muscles
- Tingling in your fingers or toes
- Trouble concentrating
- Hair loss
- Inflammation
- Swollen lymph nodes
How to Boost Your Immune System
The same things that keep your heart, brain, bones, and the rest of you well are also good for your immune system.
Vitamins for the immune system
You need plenty of vitamin C andvitamin Dfor your immune system to function properly. But you also need vitamins A, B6, B12, E, and K. You can get these pretty easily through a balanced diet or supplements.
Foods that boost the immune system
While no single food will boost your immune system, your diet is a great way to supplement minerals that are important for supporting your immune system. Add foods rich in folate, copper, iodine, iron, magnesium, selenium, and zinc to your daily diet. Look for foods such as:
- Leafy green vegetables
- Orange and yellow vegetables
- Citrus fruits
- Broccoli
- Fatty fish, including salmon and tuna
- Nuts, seeds
- Oysters, crab, lobster
- Garlic
Other ways to boost your immune system
- Stay active.
- Maintain a healthy weight.
- If you smoke, quit.
- Drink alcohol in moderation.
- Get enough sleep.
- Keep your vaccines up to date.
- Manage your stress.
Takeaways
Your immune system is your body's defense against viruses and infections. It protects you from getting sick and heals you when you are sick. Your white blood cells are an important part of your immune system because they help fight infection and disease. Your immune system does weaken as you age, but you can boost it by eating a nutritious diet, exercising, and getting enough rest every night.
