Deadliest Diseases Worldwide
1. Ischemic heart disease, or coronary artery disease
The deadliest disease in the world is coronary artery disease (CAD).
Also called ischemic heart disease, CAD occurs when the blood vessels that supply blood to the heart become narrowed.
Untreated CAD can lead to chest pain, heart failure, and arrhythmias.
An increasing life span, socioeconomic changes, and lifestyle risk factors play a role in this rise.
Risk Factors and Prevention
Risk factors for CAD include:
high blood pressure
high cholesterol
smoking
family history of CAD
diabetes
having overweight
Talk with a doctor or healthcare professional if you have one or more of these risk factors.
You can prevent CAD with medications and by taking steps to improve heart health. Some of the ways you can decrease your risk include:
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 (Cerebral Vascular Accident)
A stroke occurs when an artery in your brain is blocked or leaks. This causes the oxygen-deprived brain cells to begin dying within minutes.
During a stroke, you feel sudden numbness and confusion or have trouble walking and seeing. If left untreated, a stroke can cause long-term disability.
Strokes are the leading cause of long-term disabilities. People who receive treatment within 3 hours of having a stroke are less likely to have disabilities.
Sudden numbness on one side is a symptom of a stroke.
Risk Factors and Prevention
Risk factors for stroke include:
high blood pressure
family history of stroke
smoking, especially when combined with oral contraceptives
being African American
being female
Some risk factors for strokes can be lowered with preventive care, medications, and lifestyle changes. In general, good health habits can lower 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 drinking 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)
Viruses usually cause lower respiratory infections, but they can also be caused by bacteria.
Coughing is the main symptom of a lower respiratory infection. It may produce sputum.
You may also have a fever, sweating, or chills, or experience breathlessness, wheezing, and a tight feeling in your chest.
Risk factors for lower respiratory infection include:
the flu
poor air quality or frequent exposure to lung irritants
smoking
a weak immune system
crowded childcare 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.
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 makes breathing difficult.
Chronic bronchitis and emphysema are types 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 way to prevent COPD is to stop smoking. Avoid secondhand smoke and other lung irritants.
5. Tracheal, Bronchi, and Lung Cancers
Respiratory cancers include cancers of the trachea, larynx, bronchi, and lungs.
The main causes are smoking, secondhand smoke, and environmental toxins.
Household pollutants, such as fuel and mold, also contribute.
Tracheal, bronchi, and lung cancers can affect anyone, but they’re most likely 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.
6. Diabetes mellitus
Diabetes is a group of diseases that affect 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 several factors, including poor diet and physical inactivity.
Over time, uncontrolled diabetes can cause damage to the nerves and blood vessels. This can lead to complications such as impaired wound healing, kidney failure, and blindness.
Risk factors for diabetes include:
being overweight or obese
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 control 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.
The disease starts by causing mild memory problems, difficulty recalling information, and slips in recollection.
As the disease progresses, you may not have significant memory problems.
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.
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.
Risk factors for diarrheal diseases include:
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 is 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.
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 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 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 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.
Frequently asked questions
How many rare diseases are there?
A rare disease is usually defined as a disease or condition that affects fewer than 200,000 people in the United States.
According to most scientists and clinicians, there are around 7,000 different rare diseases.
Some rare diseases are hereditary and can be passed from parent to child. Some may be visible from birth, while others might show up later in life.
Which disease has no cure?
There’s no known cure for many conditions, including several on the list of the deadliest diseases.
This also includes conditions such as cancer, Alzheimer’s disease, multiple sclerosis, pulmonary fibrosis, and muscular dystrophy.
In many cases, certain lifestyle factors, such as smoking cessation and modifying your diet or exercise routine, may lower the risk of developing some of these conditions.
In other cases, a combination of lifestyle changes, medications, and other treatment methods might help manage or reduce symptoms of a condition, though it may not necessarily cure it.
What’s the deadliest disease?
Ischemic heart disease is the leading cause of death around the globe.
Other conditions, such as stroke, COPD, lower respiratory infections, and respiratory cancers, also account for a significant portion of deaths each year.
Takeaway
While deaths from certain diseases have increased, those from more serious conditions have also decreased.
However, many of the diseases on this list are preventable and treatable, and as medicine continues to advance and education grows, we may see improved outcomes for many of these diseases.
A good approach to lowering your risk of any of these conditions is to follow a balanced diet, live a healthy lifestyle, and stay active.
Moderating your alcohol intake and quitting smoking, if applicable, can also help.
For bacterial or viral infections, proper handwashing can help prevent or lower your risk.
