Differential Diagnosis for Sighing Dyspnea and Low Blood Pressure

Single Most Likely Diagnosis

• Anxiety Disorder: Sighing dyspnea can be associated with anxiety disorders, which can also lead to hyperventilation, contributing to low blood pressure due to decreased carbon dioxide levels in the blood. The chronic nature (2 months) suggests a condition that is not immediately life-threatening but significantly impacts quality of life.

Other Likely Diagnoses

• Cardiac Conditions (e.g., Heart Failure, Cardiomyopathy): These can lead to dyspnea and potentially low blood pressure due to decreased cardiac output. The sighing aspect might be less typical but could be part of a broader symptom complex including anxiety related to the underlying condition.
• Chronic Obstructive Pulmonary Disease (COPD) or Asthma: Both conditions can cause dyspnea. While they might not directly cause low blood pressure, the physical exertion of breathing and potential for respiratory failure could indirectly lead to hypotension.
• Deconditioning or Chronic Fatigue Syndrome: Prolonged periods of inactivity or chronic fatigue can lead to shortness of breath with minimal exertion and potentially low blood pressure due to decreased vascular tone.

Do Not Miss Diagnoses

• Pulmonary Embolism: Although less likely given the chronic nature of symptoms, a pulmonary embolism can cause sudden onset of dyspnea and potentially lead to hypotension if large enough. It's crucial to consider this diagnosis due to its high mortality rate if untreated.
• Cardiac Tamponade: This condition, characterized by fluid accumulation in the pericardial sac, can lead to decreased cardiac output, resulting in dyspnea and low blood pressure. It is a medical emergency.
• Pneumothorax: A collapsed lung can cause dyspnea and, if large, can lead to hypotension due to decreased cardiac output. It requires immediate medical attention.

Rare Diagnoses

• Mitral Valve Prolapse: While often asymptomatic, in some cases, it can lead to dyspnea and potentially low blood pressure, especially if there's significant mitral regurgitation.
• Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic high blood pressure but also orthostatic hypotension. Dyspnea might not be a primary symptom but could occur due to associated anxiety or cardiovascular effects.
• Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Some types can lead to dysautonomia, which might present with dyspnea and orthostatic hypotension.