Cat missing for a week, just came home...PLEASE HELP!

Hi everyone .... my cat Smoke is very precious to me, my niece was murdered back in '99 and he was given to her when he was a kitten as a Mother's Day present in '96. I have had him since then and have moved a couple times, and he has never run away. He is an indoor/outdoor cat (or atleast he was) and usually only went out if I was home, and came back atleast by bedtime. I could go to the door and call for him and he would come in for bed. There has only been a night or two here and there that he stayed out all night, but he was at the door first thing in the morning, that is, until recently! A few weeks ago he didn't come when I called him in the evening and was not at the door in the morning..... all day I worried about him. That night around 9pm I was going out the door to my car and there he was, casually walking up meowing! His behavior was kind of strange after that, he didn't want to go outside at all for a couple days. He also would mostly only stay in my room on my bed, and he meowed more than usual for attention (which I gladly gave him!) He would sometimes even follow me into the bathroom! The weekend of Mother's Day I went out of town and gave a neighbor my key to check on the animals and let him out for a little while, and he only went out once according to her! When I came home Monday he went out for a bit, and then came back in. Later in the afternoon he wanted out again and this time he didn't come when I called him.... he didn't show up the next morning either.... not even the next day! He stayed gone until today, which is over a week! He now has the same behavior meowing and staying in my room on my bed. He is rather thin looking and has a bit of a cough. I plan on taking him to the vet tomorrow, but have any of you ever experienced this before? I heard before that cats (outside ones) sometimes go away and die rather than dying in the home when they know they are sick or unable to live. I am wondering if he had done this, but since he was still alive he came back home for help?? Any advice would me MUCH appreciated!!!!!! Oh! And he is neutered in case any of you were wondering! Thanks ahead of time for ANY help anyone can give as to why he did this! Sorry this was so long!!

Perhaps he go tlocked up in someone else's garage or another place he couldn't get out of?? Fwan's cat last year was gone for quite some time and I think it was locked up somewhere by mistake.
Several yrs ago one on our cats was gone for a week-we could hear her meow under some spruce trees but she wouldn't come any closer. After several days she came in the garage and was hiding under the truck. We opened the kitchen door she ran inside up to the bedroom and hide under the covers for 24 hours!! She was always a bit skittish after that episode but we would let her back outside. Maybe you cat is scared still and needs reassuring. Taking to vet for a checkup is a good idea.
Give Smoke some extra attention and don't leave him outside for a while.

I would take him in rather quickly to the vet. Is he up on his vaccinations? When they get outside, and are unable to find food, they can start going downhill quite rapidly. I hope you have an early appointment

Thanks for responding guys!!! I am thinking about taking him to the pet ER, he just keeps crying and isn't acting like himself. As of right now is he laying in the floor in here in my room and just meows pretty frequently.... He hasn't gotten back up on the bed since earlier when he started coughing, he jumped down off the bed and hasn't gotten back up here since. He has a dry cough, not like (I know some may say GROSS) but not like when they have a hairball, but just a dry cough. I am just so worried about him because it's kind of like all I have left of Melissa, so he is so precious to me! Thanks again for responding, I will get on and give you an update as soon as I have one!!

Sounds like he has kennel cough. For the longest time I though only dogs got kennel cough. Cats get it too.
After the vet visit try feeding him meat baby food. It's $.85 a jar here, but it will put on weight & it's easy on their digestive systems. Let us know how he's doing.