For many years it has been known that bones are innervated with sensory neurons. Yet their exact anatomy remained obscure due to the contrasting physical properties of bone and neural tissue. More recently, it is becoming clear what types of nerves innervated which sections of bone. The periosteal layer of bone tissue is highly pain-sensitive and an important cause of pain in several disease conditions causing bone pain, like fractures, osteoarthritis, etc. However, in certain diseases the endosteal and haversian nerve supply seems to play an important role, e.g. in osteomalacia, osteonecrosis, and other bone diseases. Thus there are several types of bone pain, each with many potential sources or origins of cause.