The 10 deadliest diseases

Today we know the treatment of many of the diseases discovered, however, some are so lethal and silent that they continue to increase their death toll every year. Do you want to know which are the 10 most lethal diseases in the world? We will indicate it below.

The lethality of a disease is an epidemiological variable that reflects its severity based on the number of deaths among the sick population. Despite what most would expect, noncommunicable and chronic diseases outnumber communicable diseases in annual fatality.

The 10 deadliest diseases today

The pathologies with the highest death toll are associated with three main topics. First there are cardiovascular conditions, which include ischemic lesions at the level of the heart and brain.

On the other hand, there are respiratory pathologies due to obstructive and infectious processes. In addition, there is a high fatality rate related to prenatal, perinatal, and postnatal conditions.

Causes of death can be grouped into three categories:

  • Transmissible.
  • Non-communicable.
  • Injuries

In 2019, the World Health Organization (WHO) recorded a total of 55.4 million deaths worldwide. Within this group, 7 of the 10 most lethal diseases were non-communicable diseases.

1. Ischemic heart disease

Ischemic heart disease or coronary heart disease is the leading cause of death worldwide with 8.9 million deaths in 2019, according to the WHO. This It is produced by an imbalance between the demand and the supply of oxygen at the level of the heart muscle.

The main origin of ischemic heart disease is atherosclerosis, a product of the formation of plaques of lipids, collagen, and inflammatory cells within the arteries of the heart. In this way, there is a reduction in the lumen of the blood vessel and a decrease in the flow of oxygen.

This pathology can present as stable angina, unstable angina or an acute myocardial infarction, according to its pathophysiology and evolution. The main symptom presented is chest pain that can last between 15 and 30 minutes.

The diagnosis of ischemic heart disease is made through the anamnesis and the patient's symptoms. In addition, it can be supported by complementary tests, such as the electrocardiogram and cardiac enzymes.

Heart disease is the leading cause of death in the world and has a high fatality rate.

2. Cerebrovascular disease (CVD)

Cerebrovascular disease occupies the second place of fatality, being responsible for 11% of deaths registered in 2019, according to WHO. This pathology is part of a diverse group of conditions that generate dysfunction of brain tissue due to oxygen deficiency.

Similarly, CVD is classified on the basis of its pathophysiology as ischemic and hemorrhagic. Ischemic pathology can be temporary or permanent and is produced by the occlusion of a blood vessel. On the other hand, hemorrhagic brain injury is produced by the rupture of a blood vessel and the consequent accumulation of blood.

The symptoms of cerebrovascular disease can vary according to the area that is affected. It ranges from alterations in consciousness and orientation to disorders of sensitivity and motor skills.

On the other hand, the medical diagnosis is made based on the patient's clinic, relying on imaging tools such as CT and angio-CT. In addition, prevention and prompt treatment is crucial, as CVD is one of the leading causes of long-term disability, according to the Centers for Disease Control and Prevention (CDC).

You may be interested: The 4 most common cerebrovascular diseases that you should know

3. Chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) ranks third in the world's 10 deadliest diseases, causing a total of 3.17 million deaths in 2015, according to WHO data.

It is a condition of the airways that limits the flow of air in the lungs and that, in turn, integrates chronic bronchitis, emphysema, atelectasis and a combination of the above. In addition, it is characterized by causing shortness of breath, cough and expectoration.

Among the risk factors are cigarette smoking, air pollution and exposure to dust particles and chemicals. The diagnosis is made by clinical suspicion and by a pulmonary function test or spirometry.

4. Lower respiratory infections

Lower respiratory infections are considered the communicable diseases with the highest fatality rate in children and adults worldwide. They are characterized by a picture of immune response to a pathogen at the level of the bronchial tree and lungs.

The etiological agents that cause infectious processes in the lower respiratory tract can be viruses, bacteria, fungi and parasites. According to a pediatric study carried out in Madrid, respiratory syncytial virus (RSV), rhinovirus and adenovirus are the main causative agents of respiratory infections in children.

Similarly, can present in the form of bronchitis, bronchiolitis, flu, influenza, and pneumonia. Symptoms include respiratory distress, cough, fever, and chest pain. In addition, it can be accompanied by clinical signs, such as wheezing and rales.

Diagnosis focuses on the patient's symptoms and paraclinical examinations. Among them, sputum tests and cultures to determine the causative agent. For its part, the treatment is symptomatic plus the addition of antibiotics or antivirals according to medical judgment.

5. Neonatal conditions

Perinatal conditions rank fifth on the list of diseases with the highest number of annual deaths, with 2 million newborns dying in 2019. However, fatality has had an absolute decline in the last two decades, with 1.2 million fewer deaths than in 2000.

According to an article by the Spanish Association of Pediatrics (AEP), most neonatal deaths occur in preterm infants. Furthermore, it is estimated that the prematurity rate in Spain has been increasing in the last 20 years.

For its part, another study carried out in the United States highlights 4 topics that make up the main causes of death in neonates:

  • Genetic malformations at the level of the heart and central nervous system.
  • Respiratory pathologies.
  • Infectious processes.
  • Bleeding disorders.

Discover: How to prevent birth defects before pregnancy?

6. Cancer of the trachea, bronchus and lung

Neoplastic processes at the level of the trachea, bronchi and lungs were considered rare and not very lethal at the beginning of the 20th century. However, this condition has escalated to become a pandemic in the 21st century.

Nowadays, lung cancer is listed as the leading cause of cancer death worldwide, with a total of 1.38 million deaths for 2008 according to the European Respiratory Society (ERS). In fact, the 5-year survival for men is only 11.2% and for women 13.9%.

The evolution and lethality of this condition can vary greatly according to the histological presentation of each patient. One study highlighted that more than 90% of primary tumors of the trachea and main bronchi in adults are malignant, the most common being adenoid cystic carcinoma and squamous cell carcinoma.

On the other hand, the main symptoms and signs of neoplasms of the respiratory tree are the shortness of breath, cough, weight loss, hemoptysis, and bone pain. The method of choice for diagnosis is tomography, while treatment may include surgery, radiation therapy, and chemotherapy.

7. Alzheimer's and other forms of dementia

Patients with Alzheimer's present with a progressive deterioration of normal mental functions. This especially in women, who according to the WHO, constitute 65% of world patients with dementia.

Alzheimer's is the leading cause of dementia in the world, accounting for 60% to 80% of cases, according to the Alzheimer's Association. The initial symptomatology is short-term memory loss with changes in mood and behavior, as well as decreased orientation and reasoning.

According to a publication of dementia data in Mexico, it is highlighted that the incidence of this pathology increases as the patient is older, especially in those over 80 years old. So prevention in the elderly is of vital importance.

8. Diarrheal diseases

Diarrhea is a symptom of a vast number of gastrointestinal disorders and infections. However, watery and excessive stools can lead to dehydration. In addition, if it is not treated in time it causes death.

This heterogeneous group of diseases ranks eighth among the 10 most lethal diseases of today, causing 1.2 million deaths in 2019. WHO confirmed that diarrheal diseases are the second cause of death in children under 5 years of age , being responsible for more than 525,000 deaths of children each year.

The infectious processes that lead to diarrhea can be caused by a vast number of bacterial, viral and parasitic microorganisms. This occurs through food and water contamination or person-to-person transmission., especially in underdeveloped countries with poor sanitary conditions.

A recent AEP article establishes that rotavirus is the main causative agent of acute diarrhea of ​​viral origin in children. For its part, Salmonella spp., Campylobacter spp. and Shigella spp. they are the main agents of bacterial origin.

9. Mellitus diabetes

Diabetes and its different types of presentation occupy the ninth position within the diseases with the highest number of deaths for 2019. It is characterized by presenting high blood glucose levels, associated with poor insulin production or resistance of the body to it.

In the same way, it is considered an endocrine disorder that causes excessive thirst, increased urination frequency and increased appetite. It can be associated with weight loss, fatigue, and blurred vision in uncontrolled patients.

Diagnosis is made by biochemical measurement of blood glucose levels. For this, the oral glucose tolerance test or the glycated hemoglobin test (AC1) is used as supplements. According to a publication of the American Diabetes Association (ADA), AC1 can be used for both the diagnosis of prediabetes and type 2 diabetes.

Diabetes is diagnosed by recording the levels of glycemia in the blood, as well as the amount of glycosylated hemoglobin.

10. Kidney diseases

The number of deaths from kidney disease worldwide has been on the rise in the last two decades. In this sense, kidney pathologies have risen to 10th position with 1.9 million deaths in 2019, unlike its rate of 813,000 deaths in 2000.

Within this group, chronic renal failure stands out, which according to the Pan American Health Organization (PAHO) is very prevalent. This progressive loss of kidney function is characterized by alterations in the volume and frequency of voiding, as well as an increase in fluid retention.

So far, chronic kidney failure has no cure. So treatment is focused on relieving symptoms and slowing the progression of the disease, sometimes through dialysis.

The 10 most deadly diseases that can be prevented

Although the death rate from the 10 most lethal diseases of today is increasing, it is important to emphasize that most of these diseases are preventable and treatable.

In this sense, making small changes in lifestyle reduces the probability of suffering them. Among the modifications to be made are good eating habits, exercise, avoiding cigarettes, reducing alcohol consumption and, above all, maintaining good personal and food hygiene.