The Avengers star is prone to rashes so she often sits at home watching medical documentary shows on TV to investigate possible remedies.
Johansson admits her fascination has become an obsession and she is now able to diagnose skin conditions for her friends.
She tells Britain's Elle magazine, ""(I should be) a dermatologist. When you help someone heal their skin it gives them a new lease of life. I mean, have you ever met someone with a horrible skin condition? I'm good with that... I've had every problem. I always get these weird things (rashes)... At least I know how to cure them... I'm pretty good at diagnosing other people... It comes from watching a lot of medical programmes... Real medical programmes. Documentaries.""