Can you tell me what it means to have nociceptive back pain? And what is allodynia? Both of these words are in a medical report about my college-aged son. He doesn’t seem to remember what the doctor said about why he’s having back pain. We’re trying to get some answers and explanations before calling the doctor directly.

Low back pain usually falls under one of several different types of pain. Nociceptive back pain is a common pain pattern. Identifying which type or types of pain are present is key to choosing the right treatment. Physicians must be able to distinguish one type of pain from another. The real challenge comes when patients have more than one type of pain at the same time.

Nociceptive back pain occurs when an anatomical structure in the spine is stimulated by mechanical or chemical means. Mechanical stimulation comes in the form of compression, misalignment, or deformity. Studies using chemical stimulation have injected a dye into the joint. The added fluid in the joint expands the soft tissues and puts pressure on the nerve endings inside and/or around the joint causing pain.

Studies of nociceptive pain have used normal subjects and targeted spinal ligaments, spinal joints, discs, sacroiliac joints, and back muscles. By stimulating each of these areas individually, scientists have been able to identify responses used by patients to describe nociceptive pain as dull and/or aching.

Allodynia is a medical term for pain caused by a stimulus that normally doesn’t cause pain. For example, gentle pressure or a light touch results in moderate to severe pain. Mild hot or cold temperatures in contact with the skin can cause allodynia. Pain felt with gentle brushing the skin can also be referred to as allodynia.

The presence of allodynia as a symptom signals damage to a nerve. There is no allodynia with nociceptive pain. These are two separate types of pain caused by two separate problems.