International community usually causes the pain caused by cancer pain were divided into four categories:
Cause of cancer pain (1) As the disease itself, cancer pain (78.6%) tumors of the organs of direct invasion, oppression, and the nerve plexus invasion and oppression, the expansion in real growth of sexual organs, organs of the cavity caused by mechanical obstruction, tumor necrosis, ulceration, and changes in local inflammation.
Cause of cancer pain (2) cancer-related pain (6.0%) such as tumor-induced pain Yan ribbon tumor, tumor non-specific severe osteoarthritis pain.
Cause of cancer pain (3) pain associated with cancer therapy (8.2%) after the nerve injury, such as cancer, epilepsy, pain, scar, radiation ulcer after radiotherapy, spinal cord injury, vasculitis, etc. after chemotherapy.
Cause of cancer pain (4) associated with diseases unrelated to cancer pain (7.2%) such as arthritis, bedridden due to pressure ulcers, angular cheilitis and so on.
Unlike other diseases, pain, cancer pain, pain caused by a number of reasons, causes or sicker than not, the pain will persist, and to increase, should pay attention to determine the reasons for the time of diagnosis.