Severe back pain, often accompanied by sciatica or sciatic nerve pain, goes beyond a normal sprain and strain. Severe back pain needs a proper evaluation because it may often be difficult to diagnose accordingly. This generally needs additional diagnostic procedures to determine the cause of severe back pain and sciatica. Nociceptive and neuropathic pain can be further broken down into acute and chronic pain, which can ultimately be different. With acute pain, the severity of the painful symptoms depends on the level of tissue damage or injury. People have a protective reflex to avoid this type of pain. With this type of pain, there is a reflex that makes people pull back quickly after moving or being in a certain position. Acute pain can be a sign of injured or diseased tissue. Once the health issue is healed, the pain also stops. Acute pain is a type of nociceptive pain. With chronic pain, however, the nerves continue to send pain messages after the earlier tissue damage has healed. Neuropathy falls into this type of severe pain.