Hypothyroidism and non-cardiogenic pulmonary edema: are we missing something here?

We report the case of a 42-year-old female with a history of hypothyroidism and asthma presenting with progressive dyspnea and orthopnea after 2 days of an upper respiratory tract infection (URTI). Based on the clinical and radiological findings, the patient was admitted as a case of cardiogenic pulmonary edema secondary to possible viral myocarditis. However, a normal brain natriuretic peptide (BNP) level with a normal ejection fraction (EF) on echocardiogram changed our working diagnosis from cardiogenic to non-cardiogenic pulmonary edema. Further questioning revealed a history of nocturnal snoring, frequent awakening, and daytime fatigue, suggesting a possible sleep apnea syndrome (SAS). In conclusion, we believe that SAS was the missing link between our patient's hypothyroidism and non-cardiogenic pulmonary edema. LEARNING POINTS: Always keep an open mind and look for a pathology that would explain the whole clinical scenario. The involvement of the respiratory system in hypothyroidism can range from SAS, pulmonary hypertension, hypoventilation, and severe respiratory failure. Hypothyroidism and SAS should be considered in the differential diagnosis of non-cardiogenic pulmonary edema. Patients should be instructed to take levothyroxine on an empty stomach 30–60 min before food to avoid erratic absorption of the hormone.