About a month ago, I started to get an achy back. At first it wasn’t a big deal; my back regularly tells me when I’ve spent too long on my feet or overdone it with weights. It usually calms down in a day and doesn’t demand any more attention than a light stretch or two. However, this achy back incident was different. It didn’t go away, and after a day or so the pain began to radiate down my right leg. As an acupuncturist, I know that what I was experiencing was sciatic pain; some kind of inflammation or compression of my sciatic nerve. The pain was typical of sciatica; deep, dull, and achy.
At first, I thought what I was experiencing was a recurrence of the piriformis syndrome I had years ago, in which a muscle deep in my butt was impinging on my sciatic nerve. The pain was the same, except I had no tenderness or tightness at the site of the muscle. Then I began to suspect that I was having disc problems, as a compressed or bulging disc is often the cause of sciatic pain. Needless to say, I was hoping that was not the case.
My self-treatment for this kind of thing is to rest, apply heat, and roll a tennis ball between my back and the wall, to work out any sore spots. 
During one rolling episode, I hit a spot that lit up, not only the pain in my back, but also the pain down my leg. Bingo! When I started poking around in the area I found a small, quarter-sized lump that was the mother of all my pain. After doing a little research, I realized that what I had was an inflamed back mouse.
Back mice sound kind of cute. However, like all mice, they’re not too much of a problem…until they are. A back mouse is a term for the herniation of adipose tissue through the fascia in your lower back. In other words, it’s fatty tissue that has pushed its way through a weakened area of fibrous tissue in your lower back, also called episacroiliac lipoma. They’re actually common, occurring in an estimated ten percent of people, but more frequently in women. They can occur from accidents, falls, heavy lifting, prolonged sitting, pregnancy, or for no reason at all.
Why have you never heard of back mice? While many people have them, most don’t experience any symptoms. However, these usually benign little mice can turn ugly and become inflamed or compress spinal nerves and other tissue, causing a great deal of pain. And because the symptoms can be similar to disc problems or sciatica, back mice are frequently misdiagnosed.
In Chinese medicine, there are a number of terms for lumps and bumps. You can have concretions, conglomerations, accumulations, gatherings, and aggregations—each with distinctive characteristics. However, in the case of back mice, most practitioners would diagnose them as an accumulation of dampness and phlegm. I know, gross—but in Chinese medicine, phlegm is more than what you have when you get a bad cold. It’s considered to be congealed moisture that has accumulated to the point of causing a problem.
Furthermore, your lower back is the home to your Chinese Kidney organ system, and a sore, painful, or achy back is the hallmark symptom of your Kidney system being depleted. Kidney Yang is considered to be your body’s internal pilot light, which keeps you warm and keeps water in check. If Kidney Yang is low, you may feel chronically cold and retain water. In the case of back mice, that water has accumulated in your lower back—the area of your Kidney, and set up shop as a small lump, or two, or three.
The good news is that while many people have back mice, the majority will never know it, or at least never experience symptoms related to them. If you’re one of the unfortunate minority who have symptomatic back mice, there are a couple of things you should do and not do.
-First, do not press down on your back mice. It will not make them go back to where they belong, and will only serve to aggravate them. If you see a massage therapist for irritated back mice, ask them to take it easy and not attempt to push them back into place.
-Try a little heat or ice. I’m usually a big fan of heating a chronic injury, as it relaxes the area and increases circulation. However, ice makes tissue contract, and if your back mouse is compressing a nerve, you might try cooling it with an ice pack. My best advice: start with heat, and if that doesn’t help, try some ice.
-Give acupuncture a try. It can reduce tension around the lipoma capsule, reduce inflammation, and relieve pain. Also, acupuncture with electric stimulation may be particularly effective in treating back mice.
-Ultimately, if your pain is unbearable and your particular mouse is not calming down, it can be removed surgically. In most cases, a local anesthetic is used, the mouse (lipoma) is removed, and the underlying fascial tissue is repaired.
For my own personal back mouse, after discovering it via the tennis ball method, I quit pushing on it and applied some heat. The pain radiating down my leg went away the next day, and while the area is still mildly tender, I haven’t had any more problems with the mice in my back.
