A variety of illness, either acute or chronic, can cause SOB as the cardinal symptom leading patients to seek care, though other symptoms usually predominate. Most of those that affect the lung can be seen on chest x-ray, such as:
- Pneumothorax (punctured lung) [almost always acute]
- Pleural Effusion (Fluid in the lung’s lining)
- Chronic Pulmonary Embolism
- Lung Cancer (acute SOB if there’s hemorrhage)
- Acute Chest Syndrome in persons with Sickle Cell Disease
- Vaping marijuana (a mini-epidemic several years ago claimed a number of young lives
Then there are various other conditions. A variety of neurological diseases can paralyze the respiratory muscles we need to breathe, like Guillain-Barre Syndrome, Myasthenia Gravis, viral encephalitis, and others.
Diabetic ketoacidosis causes rapid, shallow breathing, although patients may not exactly sense SOB. Carbon monoxide and other poisonings kill by depriving the blood of oxygen, but probably begin with other symptoms like headache, confusion, nausea / vomiting, and the like.