How do I know if I have colon cancer?

If an adolescent (or an adult) is hit hard in the head, at what point should they go to the ER instead of just going to their primary care doctor?

Artificial insemination success rates seem very low. How can they be increased?

How many acupuncture treatments does it take to relieve stress? Is this something that needs continual treatment?

What is the effect of using an asthma preventer long-term? I heard that using it for years might cause bone shrinkage. Is it true?