Blood Detectives

A 60 yr old man walked into MetroHealth's ER with chest pain, a cough, night sweats. From his medical history they know a lot of things. He smoked a pack a day. Had a thing for beer. He recently lost 30 pounds without trying. He used to work in the steel mills, hadn't been overseas, likes to collect coins.

They treated him for pneumonia but he didn't get better, he got worse. And he started having hallucinations. He saw worms crawling up and down the hospital walls. He was shaking uncontrollably and confused.

Could it be alcohol withdrawal? Pneumonia and a response to infection? A stroke?

Doctors ran test after test, checking blood cell counts and sodium levels and liver function and bacterial growth and heart valves and HIV status. The pieces weren't fitting together.

Until they checked his house and ran yet another blood test.

They found jars of liquid mercury, or quicksilver--that jiggly, highly toxic stuff found in thermometers and light bulbs that scrambles your brain if you come into contact with it.

Our mystery patient -- he cleaned his coins with it.

THORNTON: The level of mercury in his blood was four times the normal limits. That was most likely causing all of his problems.

Dr. Daryl Thornton is a critical care specialist at MetroHealth.

He helped write a case study on this patient, who didn’t end up making it, for the American Thoracic Society.

Thornton says blood is one of the quickest and easiest ways to figure out what's going on in the body.

THORNTON: Blood tests are probably the mainstay of diagnosing a lot of the common disorders that we see in the hospitals.

Take heart attacks for example:

THORNTON: The protein inside of the heart muscle gets spilled out into the blood when the heart is damaged.

This sends a red alert to doctors.

Diabetes is another one. Blood tests show how you're handling sugar.

Blood can also reveal the condition of organs like the kidneys and liver.


Here at MetroHealth, Cleveland youngster Hailey-Allen latches onto her mom and cautiously gives her arm to the phlebotomist. This is the person who will draw her blood and send it off for analysis.

PHLEBOTOMIST: On the count of three…1, 2, 3….BRAGG: Ouch (crying & comforting sounds)

Phlebotomists can draw tears, especially with young children who aren’t used to getting their blood drawn. But they're prepared for that.

PHLEBOTOMIST: You want some stickers? Do you want princess or do you want Dora? BRAGG: Dora. (crying subsides)

In a typical wellness checkup, a physician might order what's called a complete blood count, or CBC. This measures the levels of red and white blood cells and platelets, and can help detect infections, blood cancers, and anemia.

Also on tap for the yearly screen might be a basic metabolic panel. It shows things like blood sugar and calcium and potassium levels.

Cholesterol is another biggie. High levels of the bad kind put you at risk for heart disease and stroke.

Name almost any condition, disease or abnormality and there’s a good chance there’s a blood test for it. How many tests in all?

THORNTON: You boy, I would refer you to one of our laboratory physicians because literally if you looked at our manual of tests that we can order from the blood, it's probably about the size of a telephone book.

Of course, it usually takes more than a blood test to make a diagnosis but it’s one of the most common ways to see what’s going on in the body. And if it doesn’t solve a health mystery, the next step could likely be…well, another blood test.

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