In his book, Lore of Running, Tim Noakes lists the ten laws of running injuries:
TEN LAWS OF RUNNING INJURIES
1. Injuries are not an act of God
2. Each injury progresses through four grades.
3. Each injury indicates a breakdown
4. Most injures are curable
5. Sophisticated methods are seldom needed
6. Treat the cause, not the effect
7. Complete rest is seldom the best treatment
8. Never accept as final, the advice of a nonrunner (MD or other)
9. Avoid surgery
10. Recreational running does not appear to cause osteoarthritis
A few notes about these laws...
Dr Noakes' point about law number one, is that injuries happen for a reason; something internal or external to the runner has caused the injury.
Law number two relates to the fact that most running injuries are gradual. This is in contrast to most injuries from contact sports. Appreciating the severity of an injury can help lead to a more rational approach to treatment.
Law number three relates to the idea that an injury has occured. Now it is time to analyze why the injury happened.
Law number five relates to the idea that most running injuries affect the soft tissues of the legs near major joints, and may not require extensive x-rays or diagnostic studies.
Dr Noakes point with law number eight, is that your adviser must be a runner. Without first-hand experience of running, this person will not have sufficient insight to help you.