
Historians' statements about prehistoric medicine are usually based on ancient archaeological discoveries. They are also often based upon comparisons with pre-literate but nevertheless modern-day societies - such as that of Australian Aborigines. These latter may or may not have beliefs similar to those held by the peoples of prehistory, there is no way of knowing for sure. The best we can say about prehistoric times, therefore, is: "It seems that..."
Some knowledge of prehistoric times will help you to understand prehistoric medicine.

Sick prehistoric people in cave, awaiting medical help from shaman
The defining characteristic of prehistoric societies is that the people of these societies could not write. They could not therefore pass on a body of medical knowledge beyond that which could be remembered. However, many of the primitive peoples that survive in the modern age seem to have built up a system of skills and behaviours that keeps them healthy in their environment, despite not having anything written down. They have done this through a process of trial and error and natural selection, and it seems likely that the people of prehistoric times were similar.
Most prehistoric peoples were nomadic - so they did not settle down and build things like hospitals, neither did they have enough consistency in their own lives to observe how all human bodies work the same. Anthropologists have found primitive tribes who have not yet realised that the sex act leads to childbirth.
The primitive technology of prehistoric peoples put them at the mercy of the elements, and led to a system of beliefs that saw humankind as being at the mercy of unpredictable spirits. These were said to bring life, death, health and disease. Such ideas led to a world in which spiritual rituals and the shaman, or witch-doctor, dominated medicine.