The 10 Most Common Respiratory Diseases

There are many common diseases at the respiratory level. From colds to lung cancer, they all have their own causes and etiology.

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 04 July, 2023

The lungs, along with the heart and brain, are one of the most important organs within the human body. Located in the rib cage (on both sides of the mediastinum), they’re responsible for oxygenating the blood and removing excess metabolic carbon dioxide . Unfortunately, there are several common respiratory diseases that compromise this process.

According to the World Health Organization (WHO), the lungs are the organs that are most vulnerable to external injuries and infections, as they’re constantly exposed to particles from the upper respiratory tract.

Exposure to smoke in the workplace isn’t the only problem; tobacco addiction continues to be one of the most common causes of death in many regions. Next up, we’ll tell you all about the 10 most common respiratory diseases, their symptoms, and epidemiological figures.

The 10 most common respiratory diseases

Respiratory disease is defined as any pathology that affects the organs and structures involved in gas exchange in animals and humans that perform mechanical respiration to obtain oxygen and dispose of carbon dioxide. As indicated by the Eurostat portal, 7.5% of deaths in the European Union are caused by this type of condition.

Respiratory diseases can affect the trachea, bronchi, bronchioles, alveoli, pleura, pleural cavity, respiratory nerves, and muscles, or even many of these structures at the same time. Some are acute and resolve on their own (such as a cold), while others are chronic and life-threatening, such as chronic obstructive pulmonary disease (COPD).

The medical specialty responsible for describing and ending these conditions is known as pulmonology. Next, we’ll explore the most common respiratory diseases and their characteristics at length.

1. Colds

As obvious as it may sound, the common cold is one of the most common respiratory illnesses in the world. According to the Mayo Clinic, it’s an infection of the upper respiratory tract (nose and throat) that can be caused by many types of viruses. It’s estimated that an adult is infected by these agents twice a year, and a child 6 to 10 times in the same period.

Although it isn’t a serious pathology, colds are the cause of 40% of absenteeism from work and 30% of school absenteeism. More than 200 viral strains cause cold symptoms, although rhinoviruses, coronaviruses, adenoviruses, and enteroviruses are the most common.

2. Lung cancer

Each year 1.8 million new cases of lung cancer occur and almost 10 million people lose the battle against it. It’s the second most malignant cancer in the world, second only to breast cancer.

While the 5-year survival rate after breast cancer diagnosis is greater than 89%, in the same interval the figure for lung cancer is 21%.

Cancer is caused by a mutation in a cell line. Cells undergo modifications at the DNA level and stop growing and dying at the normal rate. Therefore, tissue conglomerates known as tumors form, which grow unlimitedly and can spread. Smokers are 15 to 30 times more likely to develop lung cancer.

3. Asthma

Asthma is another of the most common respiratory diseases in the world. According to the WHO, this disease affects 262 million people globally and causes some 460,000 deaths annually. Asthma can be controlled with proper medication, but, unfortunately, many people in low-income countries don’t have access to it.

This chronic disease causes the airways in the lungs to narrow, and the patient has difficulty breathing with various symptoms, such as wheezing, shortness of breath, chest tightness, and coughing.

The most common asthma triggers are animals, dust mites, medications, changes in the weather, chemicals, prolonged physical activity, mold, pollen, respiratory infections, emotions, and tobacco smoke. Fortunately, bronchodilators and corticosteroids can save the lives of asthmatic patients.

4. Chronic bronchitis

According to the National Cancer Institute (NIH), chronic bronchitis is a slow-onset serious disease in which the bronchial tubes become inflamed and scarred. The overproduction of mucus in these chambers results in chronic coughing and respiratory problems. Together with emphysema, it forms the essential typology of chronic obstructive pulmonary disease (COPD).

As studies show, the prevalence of chronic bronchitis is up to 11.6%, although other sources report 2.5-3%, depending on the age group and gender. The main cause of this pathology is exposure to irritants that damage the lungs and airways.

75% of people with chronic bronchitis smoke or have smoked at some point. Exposure to irritants in the workplace, age, and genetics are also clear predisposers of this pathology. The survival rate after the diagnosis of COPD in all its variants is 10 to 20 years.

5. Emphysema

Emphysema is the second most common form of chronic obstructive pulmonary disease. Most people with COPD have both emphysema and chronic bronchitis, but the variety of both conditions varies greatly from person to person. The global prevalence of COPD as a whole ranges between 5% and 10% of the population between 40 and 80 years of age.

Emphysema can set in slowly over many years without obvious symptoms. Shortness of breath begins gradually, to the point that it hinders processes such as climbing stairs or any type of minimal physical effort.

6. Cystic fibrosis

Cystic fibrosis is a disease that causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body. It’s one of the most common types of chronic respiratory diseases in children and young people. Unfortunately, it’s a life-threatening condition.

This is the first pathology on the list that has a clear genetic character. It’s an inherited autosomal recessive disease, caused by a mutation in the gene that encodes the cystic fibrosis transmembrane conductance regulator protein (CFTR). One in 25 people is a carrier of this mutation.

As it’s a recessive trait, the harmful mutation must occur in both copies of the CFTR gene; both from the mother and from the father. A carrier and a healthy person will have 100% of healthy children, while two carriers have a 25% chance of giving rise to sick offspring.

The most common symptoms in children are growth retardation, the inability to gain weight, salty-tasting skin, incessant cough and mucus, fatigue, nasal congestion, and recurrent episodes of pneumonia, among others.

7. Pneumonia

The term pneumonia refers to the infection of one or both lungs. The presence of pathogenic microorganisms in these organs causes the pulmonary alveoli to fill with fluid and purulent substances. This condition covers a wide spectrum from mild to fatal.

Several types of bacteria can cause pneumonia. The most common are Streptococcus pneumoniae, Legionella pneumophila, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Haemophilus influenzae.

Symptoms of pneumonia include fever, chills, a phlegmy cough, shortness of breath, nausea, vomiting, diarrhea, and chest pain. Community-acquired pneumonia (CAP) has a prevalence of 10 cases per 1000 inhabitants per year and is much more common in extreme ages (childhood and old age).

8. Pleural effusion

This condition doesn’t directly affect the bronchi and bronchioles, as it does with other common respiratory diseases. Pleural effusions, as their name suggests, are collections of fluid within the pleural space. This is a virtual space that normally contains about 15 milliliters of fluid.

When the pleural cavity has more than 20 milliliters of specific lubricating fluid, the patient is considered to be suffering from a pleural effusion. It can be of the exudate or transudate type. In this last variant, congestive heart failure causes up to 72% of cases, while exudate neoplasms and tuberculosis are the frequent etiologies.

Although not all causes of a pleural effusion are respiratory in origin, the symptoms are. The most common are cough, chest pain, fever, chills, hiccups, rapid breathing (tachypnea), and shortness of breath (dyspnea).

9. Pneumothorax

The term pneumothorax refers to the presence of air in the pleural cavity; this is something that never happens in a scenario of physiological normality. As indicated by the Mayo Clinic, the air causes pressure on the lung surface and it ends up collapsing. It’s one of the most common respiratory diseases, but not as common as others mentioned.

The main symptoms of pneumothorax are sudden chest pain and severe shortness of breath. On the other hand, the causes can be mechanical injuries, COPD, cancer, fibrosis, ruptured air blisters, or failures during mechanical ventilation in the hospital environment.

10. Asbestosis

Asbestosis is considered rare in most population groups, but it has historically been one of the most common respiratory diseases in workers exposed to asbestos. According to professional documents, this material causes about 107,000 deaths annually, mostly in low-income countries.

Asbestos is an inorganic substance that progressively accumulates in the lungs after inhalation. Because protective macrophages can’t engulf it, it causes permanent damage and scarring that doesn’t heal. Common complications of asbestosis are COPD, lung cancer, malignant mesothelioma, and pleural effusion.

Many diseases, but all with common symptoms

As you have seen, there are many types with different etiologies, but they have very similar symptoms.

At this point, it goes without saying that tobacco is a killer. In fact, it kills up to 1 in 2 people who use it and 8 million people die directly from it each year. To prevent lung diseases, the best thing a human being can do is never put a cigarette in their mouth.