Medicine for Headache?

What medicine do you take when you have a bad headache? A paracetamol? What is headache? It is an effect. There is something else that is causing it. The cause could be one of the following or something else:

A Doctor’s Textbook

Every medical student is given loads of textbooks to learn from. They are required to attend clinical studies with doctors to get practical insight into illnesses. That’s wonderful. However, there is one aspect that a doctor’s textbook is missing