The Most Common Diseases

Even though we have modern technology on our side, diseases are still very much part of human life. Some are simple and can cause nothing more than a bit of inconvenience, but others are deadly and horrific in their effects. Some have had a tremendous impact in history. As mankind continue to make progress, more and more diseases would become a thing of the past, some would be controlled. For now, we would have to live with some diseases and learn how to cope with its effects.

The Most Common Diseases

Some of the more common diseases are unknown to Westerners. These are the diseases that can only be found in the tropics or are common in poverty stricken areas. There are some diseases on the other hand that are part of the life of everyone on the planet. Here are some of the most common diseases in the world today:


Influenza might not sound so menacing to most. Every once in a while a person will contract this disease and it can be very inconvenient and annoying. Though it might not sound so threatening now, influenza has a very deadly history. This disease caused one of the worst epidemics in recent history. The Spanish influenza epidemic of 1918 killed 500,000 in the United States alone. The exact number of deaths that it caused globally would never be known, but it is in the tens of millions. Even today this disease causes 20,000 deaths in the United States. The influenza virus targets the respiratory system of a human which causes high fever, coughing, fatigue, body aches and other symptoms.


This disease is something that we often encounter in accounts of travels in the tropics. It is caused by the bite of the mosquito that carries the disease. In the past it was thought that the air in swamps where the disease was common was the cause of the disease. It was only when modern medicine came about that it was realized that mosquitoes were the real culprit.

Malaria affects a staggering 500 million people yearly. Those affected are people living in tropical and sub-tropical regions. There are three stages of the disease. In the first stage the infected person will experience chills and shaking. On the second stage, there will be high fever and intense headache and on the final stage, the infected person’s temperature will drop and will start to sweat profusely. This disease was supposed to have been eradicated decades ago, but it is becoming more common again.


Dengue is another disease that spreads through mosquito bites. Globally there are 50 million cases of dengue each year. The Aedes aegypti mosquito is the one that spreads dengue through its bite and it is very common in Asia and in Africa. In recent years there has been a dramatic rise in the number of dengue cases globally.

Dengue cases can be classified as mild or moderate. Occasionally, cases can be severe and life threatening. Severe cases of dengue can develop into haemorrhagic fever which might involve failure of the circulatory system. Spread of this disease can be prevented by making sure that the Aedes aegypti will not have breeding grounds in places where there human habitation. Keeping a clean environment can go a long way.

Hepatitis B

You might be surprised to learn that Hepatitis B is the most common infectious disease in the world today. Over 2 billion people are infected with the Hepatitis B virus and of that more 350 million will never be able to get rid of the virus from their body. There are several symptoms caused by Hepatitis B and that would include jaundice, fatigue, stomach pain and vomiting. Because this diseases causes inflammation of the liver, it can develop into liver cancer as the infected person grows older.


Cholera is a disease that spreads because of dirty drinking water and unclean conditions. It is very common in the Indian sub-continent, in Russia and in Africa. It is caused by the Vibrio cholera and it affects the intestines. It can cause severe diarrhea in the infected person. Severe cases will develop leg cramps and vomiting and can lead to death because of dehydration.

Like other diseases in the past, it was thought that cholera was caused by something in the air and people in some parts of the world tried to control its spreading by fumigating their cities. Today, the World Health Organization reports that there are 200,000 yearly of cholera all over the world.


Measles has been eradicated in the developed countries but it is still a problem in the developing world. In 2006 alone, there were 30 million cases of this disease that was reported. Of those, there 242,000 deaths reported. Hopefully this disease would be completely eradicated in the near future with the use of vaccines.

The symptoms of Measles include high fever, coughing and rashes. It can cause pneumonia and diarrhea which can be very risky for infants who are the ones who usually fall victim to this disease.


Meningitis is also commonly known as spinal Meningitis because it affects the spinal cord. It can be caused by either a viral or a bacterial infection on that part of the body. Meningitis that is caused by bacteria is normally more severe than those caused by virus. It can cause loss of hearing, learning disabilities and in some cases brain damage. More than a million cases of bacterial Meningitis is reported yearly.

River Blindness

River blindness is caused by the larva of a parasitic worm, the Onchocerca volvulus which is found in Africa. More than 18 million cases of this disease is reported in Africa. More than 200,000 of those infected with the disease have been reported to have lost their sight.


Tuberculosis is another major killer. Authorities estimate that this disease causes more than 2 million deaths every year, though progress has been made towards controlling it. Despite the progress, WHO estimates that between 2000 to 2020 about a billion people will be infected with Tuberculosis if drastic steps are not taken to control it.

Tuberculosis is caused by bacteria which usually affects the lungs. It can cause severe coughing that brings up bloody phlegm.

Typhoid Fever

With an estimated 17 million cases annually, Typhoid Fever is really one of the major diseases that the world has to deal with. It is common in developing countries where there is scarcity of clean water and food. Symptoms of Typhoid fever include high fever, headache, nausea and loss of appetite.

Yellow Fever

There are 200,000 cases of Yellow Fever every year and that leads to 30,000 deaths. There are two phases of the disease. The first phase would involve fever, muscle pain and head ache. Most infected persons would recover from that phase after 3-4 days but 15% of those who suffer from this disease will enter the 2nd phase which could lead to kidney failure.


Experts consider the HIV/AIDS problem to be the worst pandemic in modern history. This disease has had a major impact in the modern world. But its impacts are felt the most in African countries where huge portions of its population are infected with the disease. According to WHO since the start of the epidemic more than 70 million people have been infected with the disease and half of those have died already.

AIDS is caused by HIV and it attacks the immune system of the body. By itself it is not really fatal but because it takes away the defence of the body, leaving it exposed to other disease, it will eventually cause the death of the infected person unless serious medical intervention is made. The disease can have a wide variety of symptoms and some infected persons might not even experience any symptoms at all.

AIDS was first reported in 1981 in the United States, but it is believed that it originated in Africa. Since then major research has been poured towards studying this disease and finding a cure for it. Unfortunately, there is still no cure for AIDS though there have been some progress made towards controlling it. The biggest breakthrough in the fight against AIDS is the development of the antiretrovirals (ARVs) and the use of these drugs in cocktails. Antiretrovirals (ARVs) do not cure AIDS but they have reduced the mortality of those infected with the disease. There is on-going research right now to bring these medicines to the people of the developing countries.

Most of the diseases that we have mentioned here can be prevented by making sure that our surroundings stay clean and that the food and water that we use are safe and free from contamination. Other diseases on the other hand would require a change in our lifestyle and in our habits. Research must continue in order to find better medicines and better ways of curing some of these diseases and making those cures available even to the poorest countries in the world.