Some Problems with Lab Tests.

My new Clinical Medicine professor has ran over 1000 running races and has ran 52 marathons. Incredible! (Note: A marathon consists of running 42.2 kilometers in one period of time. The average time to complete a marathon is 4 hours and 32 minutes, while the fastest runners in the world complete the race in just a bit over 2 hours).

This new professor is teaching us all about laboratory tests. Before he got to the nitty-gritty of it, he talked to us about all of the problems associated with lab tests:

- The wrong fluid/cell/molecule is measured for the test.
- Lab tests are designed for sick people, not healthy 'normal' people.
- The wrong fluid/cell/specimen collected.
- The specimen was handled correctly.
- The patient was prepared wrong (e.g. patients need to be educated what a fast means, that they can't smoke before a test, no coffee in the morning of a test)
- The sample was taken at the wrong time (e.g. metabolic changes occur two hours after eating, was the test taken at this time (if the test is aiming to evaluate a metabolic parameter))
- Need appropriate reference range (the best reference range is yourself, when you are healthy. My prof recommends that everyone get their blood work done when they are perfectly healthy and then keep these results with them and to use as a comparison when blood work is required when they are sick).
- Most measurements should be of what is going inside the cell and not the fluid around them (i.e. blood, serum); however it is very hard to measure intracellular activity, so labs estimate cell activity by using the surrounding fluids (not the best measurement, but easier to preform).

...so, I recommend that lab results be taken with a grain of salt. Lab technicians make mistakes. Doctors make mistakes in interpreting labs. Patients make mistakes when preparing for labs. Moreover, your own blood or cells can decide to show the wrong picture of your health (blood work only shows your body in a moment of time, what if that moment of time was bad, but the rest of the time the body is healthy and good?)

I'll leave you today with a funny story:

My professor has preformed pregnancy tests on men just to show their inaccuracy. When he preforms the test on men, roughly one or two men (out of one hundred) test positive! One reason why is that the test is can make mistakes. Another reason why is because some men use the pregnancy hormone to boost their testosterone levels (illegally), for sports or training purposes.


  1. Hello,

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  2. 42.2km! That's like running from where I live now to my childhood house and back! You must need to be in excellent shape for that kind of work out!


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