Hey there,
If it persists, get it checked out. About 3 years ago I noticed a loss of my falsetto and I would lose my voice on about a weekly basis. I was a smoker and I had some reflux problems. I since quit smoking and got the reflux under control, but I needed surgery to repair my voice a little over a year ago. I had a vocal cyst/pollyp on one of my vocal cords. They said it was caused by a tramatic event, but the smoking and reflux probably contributed.
Anyway, long story short, I got surgery, going on not smoking 2 years now, and I'm doing great. It was a tough few months, but my voice is as healthy as it has ever been.
Stop smoking and get it checked out.
Here is a website I used to stop smoking:
www.whyquit.com
When you decide to quit, use it as a resource.