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 Trusted Source when the blood vessels that supply blood to the heart become narrowed. Untreated CAD can lead to chest pain, heart failure, and arrhythmias.
2. Stroke
A stroke occurs when an artery in your brain is blocked or leaks. This causes Trusted Source 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.
In fact, strokes are the leading cause Trusted Source of long-term disabilities. People who receive treatment within 3 hours of having a stroke are less likely to have disabilities.
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.
