THE 20 MOST COMMON DEADLY DISEASES - MEDICINE - 2025

Among the most common fatal diseases are cholera, yellow fever, and cerebrovascular accidents, among others. They can be classified in different ways, since some are contagious diseases, others occur due to health problems of the individual (such as heart attacks) and others are due to external agents due to lack of sanitation.

However, all these diseases have in common that they have killed millions of people around the world. For this reason, the World Health Organization decided to publish a list of the most deadly diseases of the current era.

Avian flu and hepatitis B are also common deadly diseases. Source: pixabay.com

The purpose of this action is to call on health institutions to innovate in the manufacture of drugs and vaccines, so that the development of these diseases could be avoided.

The most common deadly diseases in the world

Ischemic heart disease

This disease occurs due to arteriosclerosis that develops in the coronary arteries; These arteries are responsible for providing blood to the heart muscle. In 2008, this disease killed almost eight million people.

This phenomenon is due to an accumulation of fat and collagen that causes the coronary arteries to become clogged. Therefore, this condition can be avoided by maintaining constant control of LDL cholesterol values. Tobacco is also one of the reasons why this disease occurs, so it is preferable to avoid its consumption.

Obesity also causes the emergence of this disease, so it is recommended to avoid fats, sugars and highly processed food products. Physical exercise is essential to keep the heart muscle healthy.

Strokes

Strokes occur when the particular blood supply to a part of the brain is obstructed or reduced. As a result, it is not possible for oxygen and nutrients to enter the brain, so neurons begin to die in just a few minutes.

There are several categories of strokes. The most common of these is ischemic stroke, which can be divided into two groups: thrombotic stroke and embolic stroke.

There are some factors that increase the possibility of suffering from this disease, such as being overweight or obese, lack of physical activity, very high consumption of alcohol or drugs, smoking (or second-hand inhalation), high levels of cholesterol and diabetes.

Respiratory tract infection

There are many kinds of respiratory infections that may seem common and harmless; However, if they are not treated in time, they can lead to the death of the patient. Some respiratory infections can be viral or bacterial. Lung infections (pneumonia) can also occur, which are much more serious.

Among respiratory infections we find acute rhinopharyngitis -also known as the common cold-, pharyngitis and rhinosinusitis. In many cases, these conditions require antibiotics, since they can cause very high fevers in the patient.

Chronic obstructive pulmonary disease (COPD)

This disease consists of an inflammation in the lungs that obstructs the flow of air. As a consequence, those who suffer from this ailment have breathing difficulties, a lot of coughing and mucus. Even the patient can produce a kind of hiss every time he breathes.

One of the causes of COPD is prolonged exposure to irritating particles or gases, such as cigarette smoke. COPD can also lead to lung cancer if it is not treated properly.

In developed countries, COPD is caused in most cases by smoking, while in developing countries it is usually due to continuous exposure to combustible gases that are used daily for cooking or heating in homes poor ventilation.

Diarrheal diseases

Diarrheal diseases occur due to an infection in the digestive tract, mainly caused by bacteria, parasites, or viruses. The first symptom of these diseases is diarrhea, which consists of a liquid stool more than three times a day.

Diarrhea tends to spread during summer days, as the heat favors the growth of bacteria; Furthermore, dehydration also contributes to these diseases. It is best to treat them in time, since it can be a case of cholera.

Diarrheal diseases are one of the main causes of premature death in children under five years of age, which is why it is considered one of the most lethal diseases.

Children who are malnourished are more likely to get this infection. The ingestion of contaminated water also favors the bacteria that cause this disease.

HIV AIDS

The human immunodeficiency virus is called HIV, which is characterized by destroying the body's defenses by eliminating certain cells belonging to the immune system. By damaging the body's defense system, those infected are more likely to become seriously ill, and even die.

This virus is transmitted through sexual intercourse and through blood and other body fluids, so women who have HIV and are in a state, infect their child immediately at birth.

There is not a cure for this disease; however, there are ways to take care of yourself and to stay healthy to reduce the chances of getting worse or spreading the virus.

Cancers of the trachea, bronchi, or lung

Lung cancer is the deadliest of all cancers; it has killed more people than breast and colon cancer. This cancer can develop in the trachea, in the bronchi or in the lungs, since they are organs that are linked through the respiratory system.

One of the main causes of lung cancer is cigarette smoking, since 85% of patients are smokers or were smokers at some point in their lives. Other causes may be secondary (passive) exposure to cigarette smoke and continued exposure to asbestos or contaminated gases.

These cancers can also be due to genetics; furthermore, those who have suffered from chronic obstructive pulmonary disease are prone to developing these types of cancer.

Tuberculosis

Tuberculosis consists of a bacterial infection that develops as a result of the Mycobacterium tuberculosis germ. This bacteria usually lives in the lungs, but it can also harm other parts of the body.

One of the reasons TB is so dangerous is because it is easily spread; the bacteria are carried through the air when the person coughs, talks or sneezes. Some symptoms are severe cough, noticeable weight loss, fatigue, fever, and coughing up mucus or blood.

A few decades ago this disease was not curable; however, it can now be eradicated.

Diabetes mellitus (DM)

Diabetes mellitus (DM) is called a set of physical disorders that occur in the metabolic area. Its main characteristic consists in the high presence of glucose in the blood; This is because there is a problem with the production of insulin.

People with diabetes also suffer loss of vision - this can lead to blindness - and the kidneys deteriorate, which in many cases requires transplantation.

Symptoms of DM are the need to urinate constantly, increased need to feed (abnormally), extreme thirst, and weight loss.

Diabetes is a genetic disease; however, excessive consumption of gluten can promote the appearance of this. Therefore, pregnant women are recommended to eat a gluten-free diet during the development of pregnancy, so that the baby has less chance of developing diabetes.

Hypertensive heart disease

Hypertensive heart disease is a disease that consists of a series of heart problems that are caused by high blood pressure. In a hypertensive heart, the walls of the ventricles thicken, so the heart has to work harder.

In most cases, hypertension has no symptoms, so people can suffer from this disease without realizing it. However, those who suffer from hypertension can live for many years with proper treatment without presenting major inconveniences.

If high cholesterol intake is added to hypertension, this can thicken the walls of the blood vessels, leading to a heart attack or stroke.

Ebola virus disease

Ebola hemorrhagic fever is a virus that spreads easily from person to person and is transmitted by wild animals. The first time this disease broke out was in 1976, in a village in Africa near the Ebola River (hence its name).

In 2014 a new outbreak emerged in West Africa, but this time it was much more extensive and deadly than in the year of its discovery. Between 2014 and 2016, the virus spread to other countries, reaching the borders of Liberia and Sierra Leone. This resulted in a large number of deaths.

Once the virus enters a community, it spreads through direct contact with body fluids (mucous, secretions, blood, among others). Symptoms are fever, weakness, and aching muscles, head and throat, followed by severe diarrhea, vomiting, and rashes.

Zika virus disease

This virus is transmitted through mosquitoes and its first appearance was in 1947, in Uganda. Subsequently, it has been spreading until it reaches the Americas and Asia. It also began to manifest itself in Pacific territories.

In 2015, scientists realized that there is a relationship between this disease and microcephaly in newborns; If a pregnant woman is infected by the Zika-carrying mosquito, there is a possibility that the baby will suffer this consequence at the time of delivery.

Its symptoms include fever, muscle aches, skin rashes, and joint pain.

Crimean-Congo hemorrhagic fever (CCHF)

The case fatality rate for Crimean-Congo hemorrhagic fever can be as high as 40%. CCHF is a disease caused by a virus that is transmitted by ticks.

It is an endemic disease in the areas of Africa, the Middle East and Asia, since they are countries located below 50 ° latitude, which constitutes the ideal geographical area for this insect.

Most of the people who are infected with this virus tend to belong to the livestock and agricultural industry, or work in veterinary establishments and slaughterhouses.

Lassa fever

This fever consists of an acute hemorrhagic disease caused by the Lassa virus. It is transmitted to human communities through contact with food or household items that have been contaminated by rodent droppings.

This disease is endemic to the territories of West Africa and can be transmitted from person to person, especially in those laboratories or hospitals where the necessary precautions to control the infection are not taken.

Chagas disease

Chagas disease is a disease of the tropical parasitic type caused by Trypanosoma cruzi. This condition affects not only humans, but also various wild vertebrate animals. Chagas disease is endemic to the Americas (exactly 21 countries in Latin America), and affects more than twelve million people.

In addition, this tropical disease is in the category of "neglected", since at present the necessary measures have not yet been taken to end this disease. According to scientists, 12,000 people die each year as a result of Chagas disease.

Hepatitis B

Hepatitis B consists of a severe inflammation of the liver, whose organic function is to help digest food and eliminate a large part of toxins. Symptoms include a particular discoloration of the skin (turns yellow), dark-colored urine, flu-like sensations, and pale stools.

The virus is transmitted through blood and other bodily fluids, its main vehicle being contact during sexual intercourse. Approximately 686,000 people die each year as a result of this disease.

Cholera

Cholera is a disease whose main characteristic is acute diarrhea, caused by the ingestion of water or food that is contaminated by Vibrio cholerae.

This disease had its greatest peak in the late 19th and early 20th centuries; However, today it continues to claim the lives of a large number of people, reaching a total of 143,000 deaths per year.

One of the causes of the spread of cholera is due to humanitarian crises around the world, where basic sanitation and drinking water requirements are not met. Therefore, one of the ways to counteract this disease is to improve the quality of life of people around the world.

Rift Valley Fever (FVR)

Rift Valley fever is a viral zoonosis that generally occurs in animals; however, it can also be generated in humans.

RVF is spread through contact with the blood or organs of infected animals; Furthermore, it was discovered that mosquito bites can also cause this fever.

The first outbreak was registered in 1931 in the Rift Valley, located in Kenya - hence its name - and since then several outbreaks have been reported on the African continent.

Between 1997 and 2000, a very aggressive outbreak occurred in the territories of Egypt, Saudi Arabia and Yemen, increasing the possibility of RVF spreading to Europe and Asia.

Avian flu

This disease refers to a form of flu that mainly affects birds, but can spread to people.

Infected birds spread the flu through feces, saliva, and nasal secretions; For this reason, the humans who are infected with this disease are those who work directly with poultry, especially on farms.

This flu has a high pandemic potential, which is why it constitutes a notable alarm for health organizations and is a serious threat to the population.

Yellow fever

It is an acute viral disease that is also characterized by being hemorrhagic. Like many other diseases in the tropics, yellow fever is transmitted by mosquito bites.

The main symptoms are jaundice - hence the nickname "yellow" -, nausea, vomiting, muscle aches, fever and tiredness.

In the most serious cases, the patient can die within 7 to 10 days. The virus is endemic to countries with tropical climates, so it can outbreak in the Americas and Africa. Despite how dangerous yellow fever is, it can be prevented with vaccinations.

Other diseases not so frequent but also lethal

Creutzfeldt-Jakob disease (CJD)

This disease affects the elderly. 90% of patients die in a year. Some symptoms are involuntary movements of the legs and arms, memory problems, blindness and others.

Gerstmann-Sträussler-Scheinker syndrome (GSS)

It is a prion disease that affects humans from 30 to 70 years of age. Scientists have detected that it can be inherited, since certain genetic mutations are necessary to contract the disease.

Sleeping sickness

It is a disease that mainly affects sub-Saharan Africa and is transmitted by the bite of the tsetse fly.

Malta fever

Also called brucellosis, it is a disease produced by bacteria of the genus Brucella and is transmitted from other animals to humans. According to statistics, it mainly affects those who work with animals or infected meat.

The disease was discovered and described by David Bruce in 1887. There are treatments for this disease, the problem is that it is difficult to diagnose due to its multiple symptoms. 30% of the cases are local, that is, they affect a single organ or a device.

Kala-azar disease

It is produced by a protozoan. Its mortality rate per year is high, reaching up to half a million victims. There are two types of this disease: leishmania donovani (Africa and India) and leishmania infantum (Europe, North Africa and Latin America). Its symptoms include fever, anemia, and enlarged spleen and liver.

Encephalitis

It is the inflammation of the brain. Encephalitis is a group of diseases, all with different causes, but with common symptoms.

Glanders disease

In Africa, South America, and Asia, glanders disease continues to claim lives. This typical equine disease is transmitted to humans and can have 4 forms, three of which are almost fatal (septicemic, chronic and pulmonary). Its treatment is based on antibiotics (sulfadiazine and streptomycin).

Primary amoebic meningoencephalitis (MAP)

It is a deadly disease produced by an amoeba that affects the nervous system destroying its cells and replacing them with dead cells. Those infected usually die within 2 weeks. Among the symptoms of the disease is the loss of smell.

The high death rate is due to the fact that patients are difficult to diagnose, and the spread of the disease is rapid. It can be treated by administering an intravenous antifungal to the patient.

Lassa fever

It is a very common hemorrhagic fever in West Africa. It is transmitted through contact with body fluids. Its name is due to the fact that it appeared and was first described in Lassa, Nigeria.

In Africa it causes many deaths due to inadequate precautions for its treatment. Treatment is based on administering ribavirin.

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