To be immune means to be protected, and in a healthy body, this is exactly what our immune system does for us every second of the day. It does this with the use of specialised cells, tissues and organs, both inside and outside the body, to help keep pathogens - bacteria, virus, fungi and parasites - at bay.
However, before the immune system is fit for purpose, it is crucial that it can differentiate between cells that are 'self' and those which are 'non-self'.
Self are our own healthy cells and the ones that need the immune system to protect them and everything else is non-self.
Auto-immune diseases are instances in which the immune system mistakenly attacks its own cells (self) causing localised or wide-spread damage. This also explains why anyone who has received a donated organ needs to take immune suppressant drugs to stop the immune system from attacking what is essentially an organ comprised of non-self cells.
Our immune system starts with:
Skin, nails & hair
These provide us with our first physical line of defence and help to keep pathogens outside the body. It is important to remember that lots of pathogens live harmlessly on the skin and will not cause us any problems until an injury (cut or graze) enables access into the body.
Mouth
Both a layer of mucus and our saliva provide a strong line of defence. If pathogens are ingested, they are typically trapped and swallowed into the stomach where the high levels of stomach acid kill them off.
Nose
The nostrils are lined with mucus and tiny little hairs that are called cilia. Together they trap any circulating pathogens and the resulting congealed nasal mucus (snot) is either swallowed or expelled into a tissue (hopefully).
Eyes
Our eyes are protected by eye lashes and eye lids to help keep them physically safe and tears that can help to wash pathogens away and help aid recovery.
Deep inside the body, a much more intelligent level of protection is in operation. The immune system functions as two crucial parts: the innate immune system and the adaptive immune system.
The innate immune system
The innate system is our rudimentary, first line of defence. This system springs into action within hours of pathogens having overwhelmed the physical barriers and getting into the body, and its response is the same every time this happens.
It coordinates and dispatches an army of white blood cells called leukocytes that kill and devour any cells not recognised as 'self'. These leukocytes can be further categorised as phagocytes, granulocytes and mast cells dependent on the specialised task that each undertake.
The adaptive immune system
The adaptive immune system is our more intelligent second line of defence and this grows and develops over a lifetime with the help of its B cells and T cells. Both B cells and T cells are created in the bone marrow; however only the B cells mature there (hence B for bone marrow) and these cells specialise in collecting intelligence. The T cells migrate to the thymus (hence T cells) where they mature into fighting cells.
Within days of being overwhelmed by a pathogen, an army of B and T cells are sent to fight alongside the leukocytes. However, the intelligent B cells are also able to hone in on the pathogen and use it to create an antibody which the body then stores for life.
The next time the same pathogen attacks, the immune system can quickly identify it and release the correct antibodies for an extremely quick and efficient defence.
This finely tuned system works tirelessly to keep us fit and healthy every day and it is testament to its effectiveness that we can get up most mornings and live our lives without complaint.
However, it is important to remember that immune health is not just reliant on the physical aspect of our body, but also on the emotional and mental aspects too.
Emotional issues, such as the feelings encountered after loss, a relationship breakdown or abuse, or mental issues such as anxiety or depression, can all have a negative impact on the functionality of the immune system too.
Our immune system functions best when there is a healthy balance between them all.
This helps to explain why some people are inexplicably struck down with illness and/ or get it worse than others despite appearing physically fit whilst other less physically fit people sail through the winter without problem.
Here are a few of the most common symptoms we experience when our immune system has been overwhelmed, along with an explanation of why it happens:
Raised temperature
Most pathogens flourish in our body at its normal temperature but struggle if the temperature changes. As the body becomes overwhelmed by a growing number of pathogens, it raises its own temperature, making it incredibly hard for the pathogen to survive. This is a normal and healthy response to an infection and the body will revert to its normal temperature when the threat has passed.
Increased mucus production
Mucus is one of the ways that the immune system keeps pathogens at bay and if the immune system detects an increase in pathogen numbers, it makes sense that our mucus production is increased to help trap and remove them, as well as clearing away our dead leukocytes and B and T cells. Coughing and sneezing are our natural way of clearing this excess mucus from the body and as frustrating as these symptoms are, they will pass as soon as the body has finished cleaning up.
Aches and pains
When the body is overwhelmed, energy is diverted away from functions, such as moving, thinking and digesting, towards the immune system where it is needed more. This depletion of energy is experienced as a global feeling of aches and pains throughout the head and body, and these symptoms will resolve as the body heals and energy is redistributed.
Inflammation
Occasionally symptoms can be more focalised into one area leaving it red, hot, swollen and painful to move. This is caused as the immune system increases the blood flow into the infected area bringing with it everything the body needs to help it fight and heal.
When everything is directed into one area, the pain can be extremely intense and/or unbearable. If movement is impossible, the pain can be alleviated by cooling the local area with ice or a cool cloth and contrast bathing it. This involves cooling the area for 5 minutes then removing it for 5 minutes. Repeat this 3 times (so ON, OFF, ON, OFF, ON, OFF) and no longer than 5 minutes as it’s the flushing action that is important here).
This helps to alternately enhance and restrict the blood flow into the area which will help reduce the heat, minimise swelling and aid drainage. However, if the pain is manageable, gentle rhythmic movement of the affected area will achieve the same thing and help the body from stiffening up.
So what can we do to help ourselves?
Eat a balanced diet
It goes without saying that a well-balanced diet provides all the nutrients the body needs to grow, repair and function well every day. However there are some food groups that are particularly important for our immune health.
ZINC: Found in oats, ginger, pecans, butter beans, lamb chops, beef steak, split peas, almonds, walnuts, sardines, peanuts and oysters
SELENIUM: Found in brazil nuts, scallops, prawns, crab, oysters, cod, lamb, garlic, brown rice, oats, apple cider vinegar and red swiss chard
VITAMIN A: Calves or chicken liver, chives, butternut squash, watercress, butter, apricots, cantaloupe melon, carrots, kale, sweet potato, spinach, parsley and swiss chard
VITAMIN C: Cherries, red peppers, kale, broccoli, watercress, cauliflower, strawberries, spinach, lemon juice, grapefruit, white or red cabbage and parsley
VITAMIN D: Vitamin D is absorbed through the skin so the best way to get your daily dose is to spend some time outdoors in the sun, or alternatively take a supplement
VITAMIN E: Sunflower seeds, almonds, peanuts, peanut butter, olive oil, spinach, asparagus, salmon, pecans, carrots and brown rice
Drink lots of water
Drinking lots of water enables our body to function at its' best. It also helps to minimise dehydration and constipation and maximise our mental capacity.
Exercise regularly
Again, it sounds obvious, but our bodies are made to move and a little exercise every day significantly helps to keep it healthy. From a small walk around the block to a high intensity gym workout, the more daily exercise the better. Movement helps to draw in fresh nutrients, flush out waste products, mobilise our joints and work the heart which collectively keep us strong and healthy and ready to fight disease when we need to.
Sleep well
Sleep requirements are different for everyone, but we all know the difference between waking full of energy and waking exhausted.
Some useful hints include
Going to bed and getting up at the same time every day
Limiting screen time, with none at least an hour before sleep
Limiting caffeine, sugary snacks, smoking and alcohol
No heavy meals before bed
Exercising every day
Give up smoking
Drink alcohol in moderation
There will be lots of occasions when our immune system is overwhelmed by a pathogen and we are ill. This is a normal, healthy part of living and our immune system is designed to cope and learn with every attack it encounters.
Knowing what we do now, the best way to help ourselves through an illness is to stay at home and rest, stay well hydrated, eat only if hungry and keep your environment well ventilated (leaving a small window open is ideal)...and let your immune system do the job it was designed to do!