What is your immune system?
The immune system has come to our attention due to the widespread media coverage of the COVID-19 worldwide pandemic. So, it is no surprise that "What is the immune system?" is one of the most frequently googled questions.
Your immune system
Your immune system is your body's defence system. The function of the immune system is to protect you against foreign invaders such as bacteria, viruses, fungi and even rogue tumour and cancer cells in your body.
Just like an army, it has military-like capabilities with several branches responsible for part of the defence. Each unit has different types of soldiers, with their specialised weapons and skills to accomplish their specific roles to protect your health.
There are two parts of the immune system.
The innate immune system
The innate immune system is fast-acting and non-selective, responding immediately to attack by the foreign invaders. Pain, swelling and fever indicate infection and that inflammation has started. The commencement of the immune response begins. Immune cells are summoned to the injury site to kill the invaders and gobble them up. It is like a sledgehammer approach.
The adaptive immune system
The adaptive immune system takes about a week to kick in. It is the smarter branch of the immune system. You may have heard of the term antibodies. Antibodies are produced to attack specific invaders. It also has a permanent memory of invaders it has encountered previously, resulting in a fast and effective response if they get into the body again.
When you receive a vaccine to prevent disease like a measles vaccination, your adaptive immune system is responsible for creating protection against the disease. You have developed antibodies from the measles vaccination, so if you do contact the measles virus, your body can overcome it fast and efficiently.
What is a "strong" immune system?
A "strong" immune system is a competent immune system. It does its job of protecting you from infection and keeping you healthy. It is neither underactive nor overactive. It is a balanced immune system.
Underactive immune system
Frequent, prolonged or chronic infections are a sign of an underactive immune system. Common chronic infections include bronchitis, sinusitis and urinary tract infections. Succumbing to cancer is also a failure of the immune system. We form microscopic tumours all the time in our body. When the earliest signs of cancer cells are spotted, special cancer-killing immune cells (NK cells) swoop down and wipe out the abnormal cells before they can grow a blood supply and become full-blown cancer.
Overactive Immune system
An overactive immune system is when the immune army attacks normal healthy cells as if they are foreign. Autoimmunity is the term used to describe an overactive immune system. There are more than 40 major autoimmune disorders, such as diabetes 1, multiple sclerosis, lupus erythematosus, rheumatoid arthritis. They all have the common feature of chronic inflammation and self-inflicted damage to organs.
Allergies are due to a hyperimmune reaction to harmless substances such as dust mites, pollen and certain foods, treating them as foreign invaders. The immune system has an overkill reaction.
Balanced immune system
A competent immune system is a balanced immune system. Your immune system should leap into action to protect you against foreign invaders. Once the attack is over, it should revert to a calm, balanced state.
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