Keeping the body's protective barrier strong against disease, infection and external attack is fundamental to health. Good nutrition, exercise and rest help maintain a strong immune system and a balanced body to cope with all kinds of foreign agents.

Every day we are exposed to millions of germs and none of us are free from being attacked by disease-causing agents such as viruses, bacteria, fungi or other parasites. Fortunately, we have a powerful weapon that defends us from these micro-organisms on a daily basis: the immune system.

This system - made up of a network of cells, tissues and organs - is always alert and ready to act as a team to protect our bodies from external agents that can enter our bodies and hurt us. And also, from internal aggressionsThe same can be done by cells in our own body that have undergone modifications. For example, tumour cells.

This "army" is capable of recognising millions of different microbes and effectively destroying those foreign bodies and enemies that reach our body. And how does it do this? Through a multi-step process known as the "immune response", in which leukocytes or white blood cells play a key role. They are the cells that allow the body to remember and recognise previous invaders and also help to destroy them.

Most of the time, our immune system does a great job, keeping us healthy and preventing infections. But sometimes problems arise that lead to illness and infection. Among the most common immune disorders are:

• • Allergies and hypersensitivity to certain substances. These are exaggerated reactions or responses of the immune system to an allergen, which in itself is harmless and innocuous. The immune response can produce symptoms such as swelling, watery eyes and sneezing and even a life-threatening reaction called anaphylaxis.

• Immunodeficiency disorders (primary or acquired). They occur when there is a decrease or absence of the body's immune response. Immunodeficiencies cause those affected to be highly susceptible to infections. Some people are born with this disorder, known as primary immunodeficiency. But immunodeficiencies can also be acquired through infection or can be caused by medication. These are secondary or acquired immunodeficiencies. These include AIDS (acquired immune deficiency syndrome) and drug-induced immunodeficiencies.

• Autoimmune diseases. In these disorders, the immune system mistakenly attacks the body's own healthy organs and tissues as if they were foreign invaders ( ). There are around 80 autoimmune diseases, among them:

1. Lupus
2. Rheumatoid arthritis
3. Scleroderma
4. Multiple sclerosis
5. Psoriasis
6. Graves-Basedow disease
7. Sjögren's syndrome
8. Type 1 diabetes
9. Hashimoto's thyroiditis
10. Addison's disease...

It is clear that the immune system is essential for our survival in a world full of potentially dangerous microbes, hence the importance of keeping it at 100%. Because with a weakened immune system, we are easy prey to infection.

To find out if your body is low in these types of defences, you should pay particular attention to certain symptomsIf you get tired under any exertion; if you have frequent urine infections, stomach infections, swollen gums, diarrhoea, constant colds, flu and sore throats or if your wounds are slow to heal, swollen and painful, it is possible that your defences are low.

Recommendations for keeping the immune system strong

Remember that the immune system is the great Security Department of your body and that strengthening it is your best defence strategy. How to achieve this? Here are some recommendations:

• • Watch your diet. Good nutrition is synonymous with health. Maintain a balanced nutrition, rich in antioxidant foods, fruits (especially those containing high levels of vitamin C), vegetables and lean proteins. Recent studies have also shown how Vitamin A (which can be found in carrots, butter and cheese) helps to keep the immune system in balance. body microbiota and, in turn, the immune system ). Avoid sugar, fat and alcohol and maintain a healthy weight.

• Get adequate rest and sleep. Restful, restful sleep is sometimes overlooked, but it is the best time to allow the immune system to recover its energy so that it can continue to work at a good level of performance. In fact, the lack of sleep can weaken your immune system.

• Manage stress. Scientists have discovered that immune system weakens in chronically stressed people. It builds up toxins in the body, wears it down and is therefore more likely to make us sick more quickly and easily. Also social behaviour may be alteredas a team of scientists recently discovered. This could mean that a malfunctioning immune system could be behind the "social deficits" typical of many neurological and psychiatric disorders.

• Exercise. It is an anti-stress activity, which helps you to release the negative energy you accumulate throughout the day and transform it into strengthening both your immune system and your muscle group.

• Hygiene and cleanliness. The simple act of washing your hands regularly removes a very high percentage of microbes and germs that can affect the immune system.

• Ventilate daily. Poorly ventilated and overheated spaces favour the proliferation of viruses.