When people think of the deadliest diseases in the world, their minds probably jump to the fast-acting, incurable ones that grab headlines from time to time. However, many of these types of diseases don’t rank in the top 10 causes of worldwide deaths.
Worldwide, an estimated 55.4 million people died in 2019Trusted Source, with chronic disorders that advance slowly accounting for 74% of those deaths. The fact that many of the deadliest diseases are largely preventable may be even more shocking.
The location of a person’s home, their availability to preventive treatment, and the caliber of their medical care are all non-preventable factors that affect risk.
World’s Deadliest Diseases in the History
1. Ischemic heart disease, or coronary artery disease
Coronary artery disease is the deadliest illness in the world (CAD).
CAD, also known as ischemic heart disease, happens when the blood channels that provide blood to the heart narrow. Arrhythmias, heart failure, and chest discomfort can result from untreated CAD.
Impact of CAD across the world
Mortality rates have decreased in several European nations as well as the United States, despite the fact that it is still the main cause of death.
This might be as a result of improved public health education, healthcare accessibility, and other preventative measures. However, the mortality rate for CAD is increasing in many emerging countries.
A growing life expectancy, socioeconomic developments, and risk factors from one’s lifestyle all contribute to this rise.
Risk Factors and Prevention
Risk factors for CAD includeTrusted Source:
- High blood pressure
- High cholesterol
- Smoking
- Family history of CAD
- Diabetes
- Being overweight
If you have one or more of these risk factors, consult a doctor or other medical expert.
Medication and actions to promote heart health can help prevent CAD. You can reduce your risk in a variety of ways, such as:
- Exercising regularly
- Reaching or maintaining a moderate weight
- Eating a balanced diet that’s low in sodium and high in fruits and vegetables
- Avoiding smoking, if applicable
- Drinking only in moderation
2. Stroke
When a brain artery is stopped or leaky, a stroke happens. The brain cells become oxygen-deprived as a result, and within minutes, they start to die.
You may experience abrupt numbness, confusion, or difficulty walking and seeing during a stroke. A stroke can result in long-term disability if it is not addressed.
In actuality, strokes are the main factor in long-term impairments. Following a stroke, people who receive treatment within three hours are less likely to develop problems.
According to a survey conducted by the Centers for Disease Control and Prevention (CDC), 93% of respondents were aware that abrupt numbness on one side was a sign of a stroke. Only 38% of people, nevertheless, were aware of every sign that would make them seek out emergency care.
Risk factors and prevention
Risk factors for stroke includeTrusted Source:
- High blood pressure
- Family history of stroke
- Smoking, especially when combined with oral contraceptives
- Being African American
- Being female
Some risk factors of strokes can be lowered with preventive care, medications, and lifestyle changes. In general, good health habits can lowerTrusted Source your risk.
Stroke prevention methods may include controlling high blood pressure with medications. You should also maintain a healthy lifestyle, complete with regular exercise and a balanced diet that’s low in sodium.
If you smoke, consider quitting and drink only in moderation, as these activities increase your risk of stroke.
3. Lower Respiratory Infections
A lower respiratory infection is an infection in your airways and lungs. It can be due to:
- Influenza, or the flu
- Pneumonia
- Bronchitis
- Tuberculosis (TB)
Though viruses usually cause lower respiratory infections, they can also be caused by bacteria.
Coughing is the main symptom of a lower respiratory infection. It may produce blood sputum. You may also have a fever, sweating, or chills or experience breathlessness, wheezing, and a tight feeling in your chest.
Risk factors and prevention
Risk factors for lower respiratory infection include:
- The flu
- Poor air quality or frequent exposure to lung irritants
- Smoking
- A weak immune system
- Crowded child care settings, which mainly affect infants
- Asthma
- HIV
One of the best preventive measures you can take against lower respiratory infections is to get the flu shot every year. People at high risk of pneumonia can also get a vaccine.
Be sure to wash your hands regularly with soap and water to avoid transmitted bacteria, especially before touching your face or eating.
If you have a respiratory infection, stay at home and rest until you feel better, as rest improves healing.
4. Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a long-term, progressive lung disease that makesTrusted Source breathing difficult. Chronic bronchitis and emphysema are types of COPD.
In 2018, about 16.4 million people in the United States reported a diagnosis of any type of COPD.
Risk factors and prevention
Risk factors for COPD include:
- Smoking or secondhand smoke
- Lung irritants such as chemical fumes
- Family history, with the alpha-1 antitrypsin deficiency gene being linked to COPD
- History of respiratory infections as a child
There’s no cure for COPD, but its progression can be slowed with medication.
The best ways to preventTrusted Source COPD are to stop smoking, if applicable, and avoid secondhand smoke and other lung irritants. If you experience any COPD symptoms, getting treatment as soon as possible improves your outlook.
5. Trachea, Bronchus, and Lung Cancers
Respiratory cancers include cancers of the trachea, larynx, bronchus, and lungs.
The main causesTrusted Source are smoking, secondhand smoke, and environmental toxins. However, household pollutions, such as fuels and mold, also contribute.
Impact of respiratory cancers around the world
A 2015 study reports that there are around 18 million new cases of lung cancer annually. In developing countries, researchers project an 81% to 100% increase in respiratory cancers because of pollution and smoking.
Many Asian countries, especially India, still use coal for cooking. Solid fuel emissions account for 17% of lung cancer deaths in males and 22% in females.
Risk Factors and Prevention
Trachea, bronchus, and lung cancers can affect anyone, but they’re most likelyTrusted Source to affect those who have a history of smoking or tobacco use.
Other risk factors for these cancers include family history and exposure to environmental factors such as diesel fumes.
Aside from avoiding fumes and tobacco products, it isn’t known if there’s anything else that can be done to prevent lung cancers. However, routine lung scans and early detection can result in more effective treatment and an improved outlook.
6. Diabetes Mellitus
Diabetes is a group of diseases that affectTrusted Source the production or use of insulin.
In type 1 diabetes, the pancreas is unable to produce insulin. This type of diabetes is believed to be caused by an autoimmune reaction.
In type 2 diabetes, the pancreas doesn’t produce enough insulin, or insulin can’t be used effectively. Type 2 diabetes can be caused by a number of factors, including poor diet and physical inactivity.
Impact of diabetes around the world
Over time, uncontrolled diabetes can cause damage to the nerves and blood vessels. This can leadTrusted Source to complications such as impaired wound healing, kidney failure, and blindness.
People in low- and middle-income countries are more likelyTrusted Source to die of complications from diabetes because of limited access to medications and technologies needed to manage blood sugar levels.
Risk factors and prevention
Risk factors for diabetes includeTrusted Source:
- Having overweight or obesity
- High blood pressure
- Older age
- Not exercising regularly
- An unhealthy diet
While diabetes isn’t always preventable, you can control the severity of symptoms by exercising regularly and following a well-rounded, nutritious diet. Adding more fiber to your diet can also help with controlling blood sugar levels.
7. Alzheimer’s Disease and other Dementias
Alzheimer’s disease is a progressive disease that destroys memory, interferes with decision making, and interrupts normal cognitive functions. These include thinking, reasoning, and other everyday behaviors.
Alzheimer’s disease is the most common type of dementia and accounts for about 60 to 70%Trusted Source of cases.
The disease starts offTrusted Source by causing mild memory problems, difficulty recalling information, and slips in recollection. Over time, however, the disease progresses, and you may not have memory of large periods of time.
Risk factors and prevention
Risk factors for Alzheimer’s disease include:
- Being older than 65
- A family history of the disease
- Genetics
- Existing mild cognitive impairment
- Down syndrome
- Unhealthy lifestyle
- Being female
- Previous head trauma
- Loneliness or social isolation
There’s not currently a way to prevent Alzheimer’s disease, and researchers aren’t sure why some people develop it and others don’t. As they work to understand this, they’re also working to find preventive techniques.
One thing that may be helpful in lowering your risk of the disease is following a healthy diet. In fact, some research suggestsTrusted Source that eating plenty of fruits, vegetables, whole grains, heart-healthy fats, and legumes could support brain function and prevent cognitive decline.
8. Dehydration Due to Diarrheal Diseases
Diarrhea is when you pass three or more loose stools in a day. If your diarrhea lasts more than a few days, your body loses too much water and salt. This causes dehydration, which can be fatal in severe cases.
Diarrhea is usually caused by an intestinal virus or bacteria transmitted through contaminated water or food. It’s particularly widespread in areas with poor sanitary conditions.
Impact of diarrheal diseases around the world
Diarrheal disease is the second leading causeTrusted Source of death in children younger than 5 years old. About 525,000 children die from diarrheal diseases each year.
Risk factors and prevention
Risk factors for diarrheal diseases includeTrusted Source:
- Living in an area with poor sanitary conditions
- Living in an area with poor sanitary conditions
- Not having access to clean water
- Age, with children being the most likely to experience severe symptoms of diarrheal diseases
- Malnourishment
- A weakened immune system
- The best method of prevention is practicing good hygiene. Handwashing, improved sanitization and water quality, and access to early medical treatment can also help prevent diarrheal diseases.
9. Tuberculosis
TB is a lung condition caused by bacteria called Mycobacterium tuberculosis. It’s a treatable airborne bacterium, although some strains are resistant to conventional treatments.
TB is one of the top causes of death in people who have HIV. Furthermore, people who have HIV are 18 times more likely to develop active TB.
Impact of TB around the world
The cases of TB have fallen 2% each year between 2015 and 2020.
One of the targets of the United Nations Sustainable Development Goals is to end the TB epidemic by 2030.
Risk factors and prevention
Risk factors for TB include:
- Diabetes
- HIV infection
- A lower body weight
- Proximity to others with TB
- Regular use of certain medications such as corticosteroids or drugs that suppress the immune system
The best prevention against TB is to get the bacillus Calmette-Guerin vaccine, which is commonly given to infants and children in areas where TB is common.
If you think you’ve been exposed to TB bacteria, a doctor can prescribe preventive medications (chemoprophylaxis) to lower the likelihood of developing an active infection.
10. Cirrhosis
Cirrhosis is the result of chronic or long-term scarring and damage to the liver. The damage may be the result of a kidney disease, or it can be caused by conditions such as hepatitis, alcoholic liver disease, or nonalcoholic fatty liver disease.
A healthy liver filters harmful substances from your blood and sends healthy blood into your body. As substances damage the liver, scar tissue forms. As more scar tissue forms, the liver has to work harder to function properly and may eventually stop working.
Risk factors and prevention
Risk factors for cirrhosis include:
- Chronic alcohol use
- Fat accumulation around the liver (nonalcoholic fatty liver disease)
- Chronic viral hepatitis
Moderating alcohol intake can help prevent liver damage and cirrhosis.
Likewise, you can prevent nonalcoholic fatty liver disease by enjoying a nutritious diet rich in fruits and vegetables and low in sugar and fat.
Lastly, you can lower the likelihood of contracting viral hepatitis by using barrier methods each time you engage in sexual activity and by avoiding sharing anything that could have traces of blood such as needles, razors, or toothbrushes.
