The scent of stress?

Can anyone out there smell stress on other people? Or Sadness, fear, anger, happiness for that matter? I seem to be able to. Able to pick out people at the store that are in a funk. Tell when family is sad or angry while their putting on an act like everything is okay. I asked someone if they have the same thing, and they seemed confused about what I was trying to ask. I don't think this is common, since I never hear anyone talk about it. XD I'm asking because today I was around someone who is always stressed or nervous, due to some mental issues, and there is this scent that follows him around. He's my Uncle, and I love him, so it has nothing to do with....well...  The smell bothers me. It's weird, it puts me on edge, and the longer I smell it the more stressed I get. I assume that would be the point of being able to smell it, to avoid whatever situation is causing it. Sometimes it's stronger then others, the more stress there is the stronger the sent. And no one else seems to smell it! What is it? Sadness has a different smell, one that drops my own mood when I smell it. I get the smell off my mom sometimes, and she'll be all,
Mom: *looks fine* "I'm okay"
Me: "No, no you're not. What is it?"
Mom: "I'm fine really."
Me: "..." *hugs*
Mom: *starts crying after a few seconds and tells me what's wrong*
This has happened more than once, and she wonders how I know. What kinda answer is "I smell it on you" ? x.x If my nose is stuffed I'm oblivious to it, so I know it really is a smell and not just me imagining it.  Because I can smell when someone is sad, I often end up talking to them about what is wrong. Happiness has a smell, and it seems to boost my mood. Anger has a smell, and I usually avoid the person until they calm down, but boy, sometimes that smell sets me off and I get all mad for no reason. I'm good at locking up my own anger though. XD I just find it strange. Oh, and I think confusion may has a sent. like if someone has been drinking, I can tell from far away way before I smell the drink, it's also a different smell from alcohol, and one that seems to pop up when someone isn't drinking either, so I sometimes confuse it for drinking when it's not.   Just wondering if anyone has the same thing.