Over the last few months I have developed a large brown patch of skin on my chest. This started out as a small patch but is now increasing in size. It doesn't hurt or itch or anything and has no raised areas. Anyone know what it is?

There are a variety of conditions that can cause this from a simple harmless pigmentation error in your body to cancerous cells.

Without seeing the patch of skin, with out a biopsy (if needed, I don't know), without knowing a lot of other things about you none of us can say what it is.

It is something to see a doctor about, it may be something for dermatologist to deal with. Again it could be many things: http://www.kamalsalon.com/dark.htm gives a short list. There are others.

Thanks David!
According to the site you gave, it sounds like staining of the skin. I really don't think it's anything to worry about but I will mention it to the doctor next time I go.