Q. I recently saw my family doctor for pain in my calf and foot. My family doctor said I have a herniated disc in my low back, so she referred me to a spine specialist. Can this be true? How can this pain be coming from something in my back?
A. When a disc herniates, the jelly-like material in the center of the disc squeezes through the torn outer ligament. The herniated nucleus presses on the nerve, joint, and ligaments. The location and amount of pressure will determine where you feel the pain. A herniated disc in your lower lumbar spine can be felt as pain as far down as your calf. If the pressure is severe, you may even feel the pain in your foot. This type of pain is called referred pain.
When there is injury or irritation in the tissues deep in the core or middle of your body, your brain cannot tell exactly where the pain is coming from. Instead, the pain is felt further away from the actual source of the problem. For example, pain in or around your heart may be felt in your jaw or down your left arm. In the same way, problems in your back can "refer" pain down into your leg. When the source of pain is toward the surface of your body, your brain has an easier time figuring out where the pain is coming from. A pinprick on the sole of your foot hurts right where the pin sticks your foot. Characteristics of referred pain include the following:
Treatment for referred pain must address the source of the pain. If your doctor has determined that your calf and foot pain are coming from your back, you will need treatment for your back, not your leg.