To deeply understand which diseases affect our respiratory system, we need to first define what the “respiratory system” is, which organs it comprises of and which function they have.The respiratory system is made up of several structures that start from the nasal cavities and reach the pulmonary alveoli; these structures allow environmental air to reach the blood to give it oxygen to receive carbon dioxide in exchange. Oxygen allows for the performance of almost all the chemical reactions that are necessary to live, whilst carbon dioxide is a waste product from the same chemical reactions performed.
The respiratory system starts with the nose and continues with pharynges, larynges, trachea, bronchi, bronchioles and finally the pulmonary alveoli, which form the lungs. All of these organs form the airways that once were divided into “upper” airways (nose, pharynges and larynges) and lower airways (bronchi and lungs); the trachea was a sort of “middle land”. Nowadays, this distinction is less used because the system is considered as a whole and this affects the evolution of pathologies that hit the single components. Such a complex structure constantly in contact with the external environment (inspired air) is potentially exposed to the aggression of viruses and bacteria while also constantly in contact with potentially allergenic substances; obviously, the system is naturally equipped with mechanical defenses and systems that correct the physical characteristics of inhaled air.It’s this vulnerability that turns into diseases mainly due to infections, but which can be favored by bad lifestyle choices, such as smoking.
The most frequent pathologies hit the nose (rhinitis), the pharynges, the larynges and trachea (pharyngitis, laryngitis and tracheitis), the bronchi (bronchitis) and the lungs (pneumonia). Starting from the nose, the more the infection goes down the more it is dangerous. As we said, these pathologies have mainly an infective cause, but we should not forget this; due to its characteristic of being an “interface” with the external world, the respiratory system is easily subject to allergic pathologies. Respiratory pathologies can be acute or chronic; the chronic form can also have new acute phases.
ACUTE RESPIRATORY DISEASES
The acute forms that hit the respiratory system derive their name from the affected tract and add the final –itis, which is present in all inflammatory forms (see chapter about inflammation), matching then the word with an adjective that specifies its characteristic. Usually the acute forms involve more organs (rhino-pharyngitis, tracheobronchitis, bronchopneumonia), probably as a consequence of the fact that, starting from the outside to the inside, each organ is a protective barrier for the next one. It is a sort of “front line” and, when it falls, the disease can continue its attack. The acute forms of respiratory diseases are mainly the consequence of a viral infection and, less frequently, of a bacterial infection that often occurs after the viral infection (bacterial superinfection), from which it is a complication. The most involved viruses, which we won’t list for brevity’s sake, are called “respiratory viruses.” It is sufficient to know that about one hundred micro-organisms are responsible for the common cold. The most dangerous respiratory virus is the influenza virus in its variants A and B and with its antigenic characteristics that differentiate the various families, giving them a combination of the letters “A” and “H” and some numbers. We all remember the A H1N1, the notorious pandemic virus that appeared in 2009-2010.
THE COLD
It is the first pathology that hits the respiratory system since the inflammation takes place in the “access gateway” of air, which is the nose. It is an inflammation of the mucous membrane (rhinitis) that increases its thickness and causes a progressive obstruction and prevents proper respiration. This is often associated with hyper-secretion and emission of mucous (runny nose), lachrymation, sneezes (a strong emission of air and droplets of mucous through the nose), photophobia (trouble caused by exposure to light) and, sometimes, headaches. It is a benign pathology that usually disappears spontaneously in three-four days; there are no causal therapies (this means the virus responsible can be fought), but there are useful symptomatic therapies based on nose decongestants, paracetamol and anti-inflammatory drugs. An abundant administration of water and warm liquids is useful as well as a day of rest so that the person will not stay in closed environments (such as schools and workplaces) where colleagues or schoolmates could be contaminated.
PHARYNGITIS
It is one of the inflammatory forms linked to the common cold of which it is a sort of a complication. In fact, because of a cold, the first defense, that of the nose and its mucosa, falls. The task of the nose and mucosa is to heat air that passes through the nose and stop the largest suspended particles in the inhaled air; the thermal shock caused by inhaled cold air can determine an inflammation of the pharynx and the development of pharyngitis, better known as a “sore throat.” Pharyngitis is associated with a difficulty swallowing (“doctor, I have the throat full of pins”) as well as a dry and often painful cough. Often, but not always, pharyingitis causes a moderate temperature, generally in the evenings. A particular type of pharyngitis is tonsillitis. This pathology affects two small organs in our throat, the tonsils, which are a sort of “gymnasium” for our immune system. In fact, the tonsils, due to their position, enter into contact with any type of microorganism (virus or bacteria) contained in the air and potentially dangerous to the body. This “close encounter” causes the development of an “immunological memory” that is able to immediately activate the defense system (anti-bodies and lymphocytes) that attack the microorganism as soon as it penetrates again. Because of this characteristic, the tonsils may mainly suffer from a bacterial inflammation that develops in pharyngitis and swell as a result; sometimes the air passage gets closed and the tonsils turn red with scattered white or white-grayish spots, named “patches.”If there are no casual therapies for simple acute viral pharyngitis, like for the cold sickness, and only symptomatic therapies, like bacterial pharyngotonsillitis, it is recommended to use antibiotics only after a doctor’s prescription. Obviously, symptomatic therapies can be associated to antibiotics to improve symptoms and, in a few cases, accelerate the healing process.
LARYNGITIS
Even this pathology is caused by inflammation, but it is different from the above-described forms. This is due to the peculiarity of the organ that is affected, the larynx, which has the only function to modulate sound caused by air emitted from the lungs and transform it into words by means of the vibrations of the vocal cords. Because of this characteristic, the diseases that affect the larynx first cause an alteration of the voice (hoarseness) or its disappearance (aphonia) to which often a sore throat, difficulty swallowing and breathing, a dry cough and a “barking” cough are associated; sometimes there is also a temperature, even if not very high. There are no drugs able to remove the cause of the disease, which is mainly of a viral origin but, apart from symptomatic therapies already described (such as anti-fever, anti-inflammatory and decongestant drugs), the use of sprays and aerosols based on cortisone (see the section relevant to asthma and BPCO for further information) may be helpful. These drugs have an anti-inflammatory effect on the vocal cords so that voice is recovered faster
TRACHEITIS
It is the inflammatory form of “passage” among the pathologies of the “upper” airways that we have described up to now and the “lower” airways that we will see later. Tracheitis is often associated to laryngitis and pharyngitis (respectively laryngotracheitis and pharyngo-laryngo-tracheitis). Also, in this case, the origin is vital and the clinical onsets are similar to those of pharyngitis and laryngitis to which it is often associated. As a consequence, the treatment is almost the same and the recommendations relevant to hygiene and food are the same. But it is important to underline that the use of inhalations or sprays based on cortisone allow the faster elimination of the disease. In fact, we don’t have to forget that, as we have said, the trachea is the “middle land” between the upper and lower airways and its capitulation, using a “battle” word, opens the access way to viruses to the bronchi and lungs. To return to treatment in the tracheitis forms, it is recommended to use drugs with a fluidifying action, such as “syrup for the cough” with an emollient effect improving symptoms, but not shortening the course of the illness.
FLU
It is a pathology included in respiratory diseases because its manifestations affect the respiratory system. The flu virus is considered the most dangerous respiratory virus in its variants A and B and with its antigenic differences that differentiate the various families, adding to them a combination of the letters “A” and “H” and some numbers. The disease caused by these viruses is called “influenza,” a word dating back to ancient times and unchanged over centuries, the origin of which refers to the influence (from which the word influenza derives) that the astral or climatic conditions were supposed to have on the genesis of the disease that recognizes a typically seasonal trend, despite the virus being constantly and endemically present in every nation.Influenza, but also the other forms defined “as a cold” and not due to the influenza virus, shows itself with a series of symptoms that goes from a sudden high fever and chills, muscular aches (myalgia), often reported as a sensation “to have been beaten”, cold, cough, sore throat and headache sometimes associated to dysphonia or even aphonia. Even if the course of the disease is mainly benign, and a healthy adult heals in three-four days without complications or consequences, it can be more dangerous for a few types of people, such as those over 65 and the chronically ill, who may have respiratory complications, even fatal.That is why, nowadays, it is strongly recommended to get a flu shot, which is suggested for everybody and in particular for weaker categories of people. Vaccinations are charged with the National Sanitary System. The vaccination, whose preparation technique guarantees a very safe and reliable product, does not protect from influenza completely, but does shorten the duration of the disease while lowering its dangerousness and, as a consequence, the risk of respiratory complications.
CHRONIC RESPIRATORY DISEASES
The OCBP (obstructive chronic bronchopneumopathy) is one of the most serious chronic diseases, both for its diffusion and its consequences. It is characterized by an irreversible, or only partially reversible, obstruction of the respiratory ways; it reveals itself through a difficulty breathing, which worsens in time, and is accompanied with a cough and phlegm. Usually, OCBP is diagnosed when the symptoms are present for at least 3 months per year for 2 consecutive years (OMS). In Italy, the disease hits about 5% of the population, up 20% in people over 60; furthermore, differently from other pathologies, this disease is constantly increasing, to such a point that it is the fourth chronic disease after arthrosis, hypertension and allergic diseases. The greatest concern is the mortality it causes. Even this contrasts other clinical conditions;, between 1965 and 1998, for the coronaropathy mortality rate decreased 59%, 64% for heart attacks and 35% for other cardio-cerebrovascular diseases, but in the case of the OCBP, there was an increase of 163%. It is calculated that OCBP causes about one million victims in the world, 18 thousand of which are in Italy. This means that, every day in our country, between 50 and 60 people, 2-3 per hour, die because of OCBP.
Between 70% and 80 % of people suffering from OCBP are smokers. This datum is not a surprise: smoking is the main cause of this disease together with atmospheric pollution and “indoor” pollution due to passive smoking and, above all in developing countries, to combustion in domestic environment. Along with a rare genetic form, due to the deficiency of the production of a particular protein, there is a certain difference in the individual predisposition to develop the disease, which explains why not all smokers will be condemned to have COBP. The early detection of the disease is extremely important and this can be done with a simple examination that measures the quantity of air breathed in and out from the lungs and the time necessary to do it. This allows for the identification of any decreased capacity of the respiratory ways, revealing if there is an obstruction to the air flow that may be treated with pharmaceutical drugs. Differently from asthma, a typical characteristic of the OCBP is that the obstruction is not reversible. Any person with difficulty breathing, or a person who is affected by a persistent cough with phlegm, especially if the person is a smoker, should go to the doctor. In fact, the diagnosis is too often too late because the symptoms are underestimated by the patient who thinks they are due to smoking. Actually, a precocious diagnosis is fundamental because it prevents the disease from worsening and allows the management of the symptoms with an improvement to the quality of life. The first recommendation is not to smoke, but there are other preventive and effective interventions. A fundamental measure is to get the flu shot. There are countless studies that prove the importance of this measure as well as other studies that confirm the efficiency of the anti-pneumococcal vaccination. This vaccination is important to protect the patient suffering from COBP because it helps to prevent acute phases and contributes in fighting the progression of the disease. The anti-pneumococcal vaccination reduces the risk of pneumonia. Research carried out a few years ago in the USA on an elderly population suffering from BPCO (1) showed that the anti-pneumococcal vaccination was able to reduce the hospitalization for pneumonia by 43% of patients and the mortality by 29%, and its benefits add to those of the flu shot. In fact, the vaccination allows the reduction of the risk of infective complications, which are one of the elements responsible for the new acute phases. This is another characteristic of the disease, which has moments of particular gravity with subsequent hospitalization of the patient. Therefore, to limit the risk, it is important that the patient gets vaccinated, leads a “healthy” life, doesn’t smoke, is attentive to the atmospheric pollution and avoids going out on days when the air is worse. Furthermore, it is important to carefully follow the prescribed therapies, also because it was observed that one of the factors responsible for the sudden changes of clinic symptomatology is due to the irregularity in following the treatment.