Acute Coronary Syndrome

**Congestive Heart Failure**
Acute decompensation of heart failure can lead to fluid buildup in the lungs, causing severe breathing difficulties[1][3].

## Pulmonary Causes

**Pulmonary Embolism**
A blood clot in the lungs can cause sudden, severe shortness of breath and is potentially fatal if not treated promptly[1][3][5].

**Pneumonia**
Severe cases of pneumonia can lead to respiratory failure and life-threatening dyspnea[1][3].

**Acute Asthma Exacerbation**
A severe asthma attack can cause extreme difficulty breathing and may be life-threatening if not managed quickly[1][3].

**Pneumothorax (Collapsed Lung)**
A sudden collapse of the lung can cause acute, severe shortness of breath[1][3].

## Other Causes

**Anaphylaxis**

**Carbon Monoxide Poisoning**

**Severe Anemia**

Citations:
[1] https://my.clevelandclinic.org/health/symptoms/16942-dyspnea
[2] https://www.medicalnewstoday.com/articles/314963
[3] https://www.webmd.com/lung/shortness-breath-dyspnea
[4] https://www.lung.org/lung-health-diseases/warning-signs-of-lung-disease/shortness-of-breath/learn-about-shortness-of-breath
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5247680/
[6] https://www.brighamandwomens.org/lung-center/diseases-and-conditions/dyspnea-shortness-of-breath
[7] https://www.nhsinform.scot/illnesses-and-conditions/lungs-and-airways/shortness-of-breath/
[8] https://www.mayoclinic.org/symptoms/shortness-of-breath/basics/causes/sym-20050890