What does a hair sample tell doctors?
My doctor took a hair sample. I'm a male and in my 40s. What is he looking for? What can it tell him?
I am not sure how to answer the question, as I am not entirely sure what your doctor is looking for or what your symptoms are. In common office practice, such as in a dermatologist's office, hair sample are most commonly taken to look for causes of hair loss. For example, looking microscopically at the root of hairs that are pulled out of the scalp with force can be helpful in diagnosing one type of diffuse hair loss, called telogen effluvium, which typically results from a severe stress to the body. Additionally, looking microscopically at hair can be used to detect the presence of several species of fungus which can infect the scalp and cause hair loss. In forensic settings and pre employment and law enforcement settings, hair is increasingly being used to test for illegal drug use. This is because drug residues remain in the hair shafts for much longer (up to a year) than in the urine or blood. Finally, in some settings, hair may be analyzed when a toxic or environmental exposure is suspected, as the residues of these chemicals can be detected there. However, these results are hard to interpret and are not used necessarily in standard clinical practice.