A 53-year-old man with a noncontributory medical history presented to the hospital with blurry vision, intermittently blue fingers, and slowly progressive dyspnea. Blood test results showed the following: hematocrit, 16% (reference interval, 40%–51%); white blood cells, 15.5 × 103/μL (reference interval, 4.2 × 103/μL to 9.1 × 103/μL); platelet count, 50 × 103/μL (reference interval, 150 × 103/μL to 330 × 103/μL). The phlebotomists had a difficult time drawing the patient's blood because it would immediately solidify in the tubes (Figure 1). 

Fig. 1. Blood sample sitting upside down on the bench at ambient temperature.


  1. What conditions could have caused blood to solidify in the tubes?
  2. What test can help determine the patient's medical condition?
  3. What steps could be taken to measure chemistry values in this sample?

Read the article here for the answers.