Extreme anemia (hemoglobin 1.8 g/dL) secondary to colon cancer.

We present the case of a 34-year-old man who presented to the emergency department with complaints of generalized fatigue and palpitations, with a heart rate of approximately 100 beats per minute and an orthostatic blood pressure of 80/30 mm Hg upon standing. A hemoglobin of 1.8 g/dL was discovered. A positive fecal occult blood test led to the diagnosis of colon cancer. Once the cancer was resected, the patient's anemia resolved.