When your child is fit as a fiddle, you tend not to think too much about his/her immune system. But given the fact that we have just come out of the rainy season and moving towards the cooler months, chances are many of us are wondering how our bodies ward off diseases.
All around us are bacteria, viruses, parasites, dust, pollen and a whole host of other substances that have the potential to make us very sick. Yet amazingly, most of us don’t get sick that often.
This is because your body is able to fend off these potential invaders with several layers of defense, otherwise known as your immune system.Not only is your immune system designed to seek out and destroy these disease causing substances, it also remembers these substances it encounters so that they are swiftly dealt with when they return in future.
Layers of defence:
When you come into contact with a foreign substance/bacteria/virus, your first layer of defense aims to stop the invader from entering your body in the first place.
It might help to think of this as a wall around a castle. Your outer layer of defense includes a physical barrier your “skin “and “bodily fluids “designed to wash away infections (your tears, mucus found in parts of the body lined with mucus glands e.g. your nose and respiratory tract)
These mucus secretions in the form of trivial runny nose and sneezing are a very effective way of protecting us from infections. Many a times we misunderstand this very protective reaction of the body as DISEASE and we hurry to suppress these very symptoms that were aimed at protecting us. Nasal sprays intended to give quick fix relief by suppressing these fighting responses of the body, unintentionally give the invaders easy excess to the nteriors of the body.
Bypassing your first defense line is like putting down a ladder across the boundary wall giving the enemy excess to the castle.
The next line of defence comes in the form of tonsils.
Tonsils are the two lymph nodes located on each side of the back of your throat. They produce white blood cells to help your body fight infection. The tonsils combat bacteria and viruses that enter your body. As the body is trying to fight against the harmful stimulus or a viral infection it gets inflamed leading to pain,redness, fever, discomfort in swelling. Many a times we think we can outsmart this God given defence and remove these gate keepers that gurad our lower respiratory tract -when in doubt cut it out. Now after having suppressed the initial defenses of the body the organisms now seem to get an easy excess to the lower respiratory tract and now the child begins to suffer from repeated lower respiratory tract infections leading to coughs.
Wikipedia defies cough as : ‘A cough is a sudden and often repetitively occurring, ‘protective’ reflex, which helps to clear the large breathing passages from fluids, irritants, foreign particles and microbes’. Unmonitored over use of cough suppressants are only bound to suppress the cough and could lead to more serious life threatening illnesses.
Many of our young patients suffering with asthma come to us with a history of such suppressions. The journey usually start with a skin rash that has been suppressed with ointments followed with repeated runny nose and sneezing. This in turn is repeatedly treated with nasal sprays followed with more frequent attacks of coughs. Only to be now diagnosed with ASTHMA. When you get an infection, besides these protective responses your body activates a complex system designed to seek out and rid your body of the infection.
This adaptive immune system , which helps your body adapt to the infection and create immunity, is some what like the castle guards who run from room to room seeking out the dangerous invaders.
Fighting an infection:
When the body senses there is a virus or other infections, foreign substance, the body reacts to try and destroy the foreign invaders. One of the first thing that happens is a type of white cell called macrophage is activated.
Macrophages recognize a foreign substance and swallow them up to destroy them. however the macrophages can be overwhelmed if they get a large dose of infection. It’s at this point the body needs to ramp up the way it fights the infection and activates other parts of the complex immune system. This includes activating other types of white cells (B-cells and T-cells).B-cells make protein antibodies that attach to the virus and label it as foreign for T cells to destroy.
After an infection has cleared, a small number of B and T cells persist in the blood with memory of the virus, allowing them to activate and destroy viruses more quickly next time they enter the body. This is known as immunity. It doesn’t really matter if the infection you’re fighting is bacterial, viral or a parasite — the general process is the same.
What is making you feel lousy?
The symptoms you experience when you come down with a cold or flu are not only the result of the infection, they are also the result of your body’s immune response to the infection. For example, Fever is the body’s response to the virus. Increasing body temperature can inactivate the virus.
When you get an infection, as well as white cells your body also activates other systems including cytokines (chemical messengers) and the complement system (a series of proteins designed to kill infections).These trigger inflammation and can cause symptoms like redness, warmth, swelling, pain. So your runny nose is actually caused by a local inflammatory response to the virus.
But you can have an infection and not actually have any symptoms. This is known as a subclinical infection. You may have got a subclinical dose of the infection where you feel a bit irritable and grumpy as you fight off the virus but don’t even realize you have an infection.
There are a number of factors that will determine whether you will get sick after you’ve been exposed to a cold or flu virus, including:
• whether you have had it before
• what size dose of the virus you got
• how infectious and virulent the bug is and
• your general health and how well your immune system is functioning.
Most healthy people have a healthy immune system and the body is always
striving to protect you or get rid of the infection. The only problem lies in our
understanding of these reactions of the body as DEFENCE or DISEASE.
Dr Dorland Martins
Consultants at VitaNova Clinics