A 48-year-old female with fatigue and shortness of breath who is in sickle cell crisis presents with clear lungs. What is the most likely diagnosis?

• A. Acute myocardial infarction
• B. New onset asthma
• C. Sickle cell crisis
• D. Pneumonia

Answer: (C)

Fatigue and shortness of breath during a sickle cell crisis most often come from acute anemia and reduced oxygen delivery due to vaso-occlusion. When the lungs are clear, it argues against a pulmonary infection or infiltrative process like pneumonia or acute chest syndrome, which would usually show abnormal lung findings or infiltrates on exam or imaging. The other options would typically present with additional clues such as chest pain and diaphoresis for a heart attack, wheezing for asthma, or fever with crackles and infiltrates for pneumonia. So the presentation aligns with a sickle cell crisis itself rather than a separate pulmonary or cardiac illness.