Is it only in your bedroom or is it also in other rooms? Can other people smell it? Or is it just in your imagination? I hope your odor is real because if not, you may have what I have which is like phantom smells. And the smells are always bad that I imagine.. I'd try to have someone come in your room that has a really good nose and see if they can pinpoint the area whee it's coming from. Get on your hands and knees, crawl around and find it. You don't want to have phantom smells.

Cats can "squirt" outside your window and it smells up the room. They do it in my garage sometimes, when they climb in through the vent.

I had this problem in my last address. The smell would come and go. Very strong some days and not at all on others. My Husband has practically no sense of smell, so frustratingly, he cant really help. When we finally moved ,it was with a sense of relief. Unfortunately 2 months after moving in to our new house the smell has turned up again, This time in our bedroom. Again it comes and goes. It smells like Tom cats spray. We have no cat. Why does it come and go? What the hell is it?

LOL! I just had to laugh out loud at the person who said 'get on your hands and knees - crawl around and find it' - the images it conjured up were really funny, though I have to agree somewhat; you would really want to find this smell if you could! I myself have this also. I had it only in my bedroom at my old address. A few weeks ago, I moved, and thought I was rid of it, but 'hey presto' - I have it here now too! Again; like another person has said; I live with someone who cannot smell anything that's put right under their nose, and so they are no help at all... But it's definitely there, and I have a very acute sense of smell which is sometimes a curse rather than a blessing! Rest assured; if this was an 'imaginary' smell, it would occur in every room and not just the one, (smell-hallucinating is not selective) and so you can bet it's really there! I've decided (however unpleasant this is) that it's our 'own' odours we are smelling which for the most part people do not usually smell their own (normally only smelling those belonging to others) and I think that the smell may be a combination of the following; 'bad breath'. Whilst we sleep, (however much one likes to think that they don't have this problem) our breath always smells because we are not opening and closing our mouths enough to freshen it up, and 'sweat' (we all sweat in our sleep at some time or other during the night) and so I believe it to be this. So in short; nothing to worry about, (however annoying) and nothing to be embarrassed about, and just hope that others who need to go into your bedroom (which should be few in number and not very often for a healthy and respectable life-style) are not blessed (cursed?) with having a sensitive sense of smell like ourselves!

are you in an apartment, maybe it's coming through the a/c vents from another apt.

OK, this is really weird but I guarantee it's authentic. I had a pair of New Balance running shoes for something like 2 or 3 years (long time) and had the same problem: my bedroom began to smell like cat urine. It took a long time to pin point it but there was some material between the top and bottom layers of the shoe's sole that had begun to deteriorate. It developed a very strong cat urine smell. I complained to the company and they replaced the shoes.