Differential Diagnosis for Severe Sudden Onset Shortness of Breath (SOB)

Single Most Likely Diagnosis

• Acute Pulmonary Edema: Given the patient's history of hypertension, which can lead to heart failure, and recent episodes of diarrhea and vomiting, which can cause dehydration and potentially lead to acute kidney injury or exacerbate heart failure, acute pulmonary edema is a highly plausible diagnosis. The sudden onset of severe shortness of breath (SOB) is consistent with this condition.

Other Likely Diagnoses

• Acute Coronary Syndrome (ACS): The patient's history of hypertension and diabetes increases the risk for coronary artery disease. Sudden onset SOB can be a symptom of ACS, especially if the patient is experiencing myocardial infarction.
• Pneumonia: Although less directly linked to the patient's history, pneumonia can cause sudden onset SOB and is a common cause of respiratory distress. Recent vomiting could potentially lead to aspiration pneumonia.
• Diabetic Ketoacidosis (DKA) with Respiratory Compensation: While DKA primarily presents with hyperglycemia, metabolic acidosis, and ketosis, severe cases can lead to respiratory distress as the body attempts to compensate for the acidosis by hyperventilating.

Do Not Miss Diagnoses

• Pulmonary Embolism (PE): Although less likely given the information, PE is a critical diagnosis to consider due to its high mortality rate if untreated. Recent dehydration from diarrhea and vomiting could potentially increase the risk of thrombosis.
• Cardiac Tamponade: This is a life-threatening condition that can cause sudden onset SOB. While less common, it's crucial to consider, especially if there's any suspicion of cardiac involvement or recent trauma.
• Aortic Dissection: Given the patient's history of hypertension, aortic dissection is a critical diagnosis not to miss. It can present with sudden onset SOB among other symptoms like chest or back pain.

Rare Diagnoses

• High-Altitude Pulmonary Edema: If the patient has recently traveled to a high-altitude area, this could be a consideration, though it's less likely without specific mention of travel history.
• Anaphylaxis: While anaphylaxis can cause sudden onset SOB, it typically presents with other symptoms like rash, swelling, and gastrointestinal symptoms. Without additional symptoms, this is less likely but remains a consideration in the broad differential for SOB.