Hair Loss: Which blood tests should be ordered ?

Blood tests for Hair Loss: Some tests are simply wasteful

There are literally dozens and dozens of blood tests that one could order for a patient with hair loss. Which ones should we order? Which ones are likely a "waste"? I enjoyed this article in the Medical Post about a newer organization in Canada called Choosing Wisely which serves to help clinicians become more aware of what tests are unnecessary.

In the world of hair loss, this concept is important. Is ordering a reverse T3 likely to add much in a patient with normal TSH? Probably not. What about an ANA level in a very healthy male with patterned hair loss - is that helpful? Probably not at all. What about ordering a transferrin saturation in patient with a ferritin of 76? Seems wasteful.

There are times when an ANA, reverse T3 and transferrin saturation are important and it is important to know when to order various tests and when not to! If one is not likely to change management of the patient if a test comes back, normal or abnormal then it makes little sense to order the test.

The Basic Tests

Basic tests in hair loss include CBC, TSH, ferritin, 25 hydroxyvitamin D and possibly extended to include zinc. Rarely hormonal tests and ANA are included but not routinely. Additional tests are really ordered on a case by case basis. For a list of tests I recommend see the following link

Basic Hair Loss Blood Tests