question: Yesterday, I had a brief experience where I smelled ammonia, very strongly, as if someone was holding "smelling salts" to my nose.  (At first I associated the smell with rubbing alcohol.) Then I felt like I needed to lie down. Then I experienced vertigo, or the room spinning. It only lasted about 30 seconds total. At the time, I was in with my physical therapist who was working on my ankle/achilles tendon. Should I be concerned? The PT wasn't sure if she smelled it or not.