Iron deficiency anemia Quiz: Ace Your Exams

A 25-year-old woman presents for evaluation of an 8-month history of fatigue. She used to run 2 miles 4 days a week, but now becomes fatigued after half a mile and feels winded when going upstairs. She reports feeling cold and needing to wear a sweater when others are warm, and she has a desire to chew on ice cubes throughout the day. She has a history of asthma since childhood which is maintained with a daily steroid inhaler. Her menstrual history is significant for a regular cycle with 5 days of bleeding with 3-4 days of heavy bleeding with clots and frequent pad changes even during the night. She eats a well-balanced diet with a variety of vegetables, fruits, lean red meat, and chicken and fish. There is no family history of blood disorders. Temperature is 37°C (98.6°F), pulse is 108/minute, respiratory rate is 16/minute, and blood pressure is 116/76 mmHg. Physical examination shows conjunctival pallor and pale nail beds. Cardiac examination shows tachycardia and a regular rate. The lungs are clear to auscultation bilaterally and the abdominal examination is unremarkable. What is the most likely diagnosis?