What Causes Raised Tiny Red Dots On Skin?

I am a 58 year old female. I have noticed many tiny red dots on my skin. They are not inflamed at all. The do not itch. They seem to be slightly raised. They are on my stomach, back and I see some very tiny ones forming on my legs. When I asked the doctor what they were I was told it was just age related and nothing to be concerned about. I don't like how they look. What are these? What causes them to form? Is there anyting I can do to prevent from gettin them?