Top 10 Deadliest Diseases in the World

By Frank Tucker | Jan 1, 2014

Written by Tony Inae, MD

Someone once asked me, if I had all the money in the world to spend on disease management, prevention and/or cure, what diseases would you spend the money to make a significant impact? Although Science and Medicine have made a lot of progress, some of the deadliest diseases that made this list claim millions of lives each year, mostly in the underdeveloped and developing nations, and many are preventable. Many of these diseases can be minimized or prevented through education, public health practices, prevention and adequate treatment. Here is my list of the top 10 deadliest diseases of the world.

10. Malaria

Malaria is a deadly disease caused by a parasite which is carried by the female Anopheles mosquito. This parasite gets transmitted through mosquito bites and travels to the human liver, where it matures. On maturity, it releases another parasite which infects the RBCs. These parasites rapidly multiply inside the bloodstream, and result in major health problems, claiming at least a million lives every year. Practicing anti-mosquito measures, taking medicine before, during and after travel, if traveling to an area where malaria is present, can prevent malaria.

9. Tuberculosis

Pulmonary Tuberculosis is a contagious infection caused by bacteria that mainly infects the lungs, but may involve other organs as well. The most common symptoms of this disease include fever, excessive sweating, fatigue, mucous and weight loss. These symptoms may become visible right away or may remain stagnant for many years. Infants, elderly and those having weak immunity are at a high risk of contracting TB. In 2011, this disease claimed approximately 1.4 million lives. Prevention primarily relies on vaccinating infants who are at increased risk of being continually exposed and appropriate treatment of those with TB, will help control and prevent the spread of disease.

8. Cancers

Both men and women who use nicotine products regularly are at a high risk of contracting cancer of the bronchus, trachea or lungs. What is even worse is that it is not only the active smokers but the passive smokers as well who are at high risk. Out of all forms of cancers, this is the deadliest, claiming around 1.3 million lives each year. Prevention includes educational awareness, adopting tobacco-free policies, and smoking cessation.


AIDS is caused by HIV, which is an abbreviation for Human Immunodeficiency Virus. The infection caused by HIV weakens the immunity of a person to the extent that he cannot fight even simple diseases like cold. When most of the T-cells or CD4 cells of the human body get killed, full blown AIDS is developed. This disease claims more than 1.78 million lives each year. Although there is no vaccine to prevent HIV and no cure for AIDS, education on protecting yourself and others from HIV infected fluids remains the mainstay of prevention.

6. Diarrheal Diseases

Diarrhea involves passing of loose or watery stools, which usually lasts for 1-2 days. But if this condition persists for at least 4 weeks, it’s defined as chronic diarrhea and can become life threatening due to loss of electrolytes and important fluids from the body, thus resulting in dehydration. Severe diarrheal conditions have been claiming around 2.46 million lives each year, mostly children in developing countries. Depending on the cause of diarrheal illness, prevention includes hand washing to prevent the spread of viruses that can cause diarrhea, and watching what you eat and drink to avoid eating anything that is contaminated.

5. Perinatal Conditions

Perinatal conditions involve complications arising out of pregnancy and childbirth, such as, hemorrhaging/severe bleeding, unsafe abortions, infections and obstructed labor, claiming the lives of half a million women and around 3 million infants, each year. The main reasons behind these deaths include inadequate medical care and nutrition during pregnancy and childbirth. Prevention is targeted towards maintaining the health of the mother, proper prenatal care, adequate medical care during and after delivery of both the infant and mother.

4. Chronic Obstructive Pulmonary Disease

Commonly known as COPD, this disease severely affects the lungs, thus making it difficult for a person to breathe. The disease can take two forms – chronic bronchitis that involves long-term coughing and mucous, and emphysema that gradually destroys the lungs. COPD is mainly caused by smoking, killing around 3.28 million people every year. The best way to prevent COPD is to not smoke.

3. Lower Respiratory Infections

These infections fall into two categories-pneumonia and bronchitis, resulting in difficult breathing, sneezing and runny nose, sore throat and headaches. These infections are difficult to diagnose, and can be caused by either a bacteria or a virus, and claim nearly 3.46 million lives every year. Vaccines are available to prevent pneumococcal disease and influenza, two of deadly causes of lower respiratory infections.

2. Cerebrovascular Disease

This disease is commonly known as a stroke, which is caused due to interruption in the blood flow to the brain. The blood vessel may burst open (hemorrhagic stroke), or there may be a blockade (ischemic stroke). As the brain does not get oxygen and blood, its cells start dying, thus causing permanent damage. More than 6.15 million people die of this disease every year. In the case of haemorrhagic stroke, controlling blood pressure through diet, exercise and appropriate medications can help keep blood pressure under control. For ischemic stroke that is often caused by a blood clot forming because of arteries becoming too narrowed from cholesterol deposits, it’s important have the bad cholesterol in the blood under control.

1. Ischemic Heart Disease

Ischemic heart disease occurs when the heart does not get enough supply of blood and oxygen on account of blocking up of the arteries. If left untreated, it can result in heart failures, and even deaths. The risk factors for this disease include high blood pressure, obesity and diabetes. Approximately 7.25 million people die of this disease each year. Ischemic heart disease is largely preventable. It is important to get adequate exercise, avoid smoking, eating healthy, maintaining a health weight, and getting regular health screenings that check for high blood pressure, high cholesterol, and diabetes. This blog is not intended to diagnose, treat, cure or prevent any disease. This blog is for information purpose only.  As always, please consult your healthcare provider if you have any health concerns and certainly before starting a treatment program.


Prev Post
Top 10 Healing Foods
Next Post
Making the Transition from ICD-9 to ICD-10