In Sciatica, Part 1 I described the health adaptations that allow you to function (almost) all the time without sciatic pain.
That was the good news. And it was important enough to warrant an article all its own.
But now – the bad news.
You’re not perfect
Despite the genius of human design, there are lots of ways things can still go wrong with the sciatic nerve.
Just to review – the sciatic nerve is a big bundle of nerves that begins in your
low back and extends all the way down to the foot, spreading its branches out
along the way.
Here’s a list (repeated from Sciatica, Part 1) of a few of the challenges the sciatic nerve has to overcome as it travels its long path to your foot:
- Your body can bend and stretch in any direction, causing straining or kinking of the nerve.
- The nerve has to pass through many muscles and connective tissue sheaths, any one of which could tighten or swell to put undue pressure on the nerve.
- The discs of the low back could bulge out, putting pressure on the nerve just as it emerges from the spine.
- Your minerals could be out of balance, with too much (or too little) sodium, magnesium, calcium, or potassium disturbing the nerve’s peace
- Poor nutrition could starve the nerve cell at its core in the spinal cord, and make it a challenge to keep sending chemical signals along its long axon.
- Impaired blood flow could leave the nerve, particularly at its end, short of energy, oxygen, or other nutrients.
In the meantime, as the sciatic nerve is struggling to cope with these potential hazards, perhaps you’ll make your situation truly impossible by getting in a car crash. Or tripping over your cat. Or getting whacked by your tennis partner’s backhand.
And even if you’re unusually blessed with the luck to avoid sitting in uncomfortable airline seats, helping your neighbor move heavy boxes, or getting thrown off your bicycle, there are other risks.
Your lifestyle habits – of exercise (or lack thereof!), diet, stress, posture, and much more – cumulatively tax your sciatic nerve.
Because of all these potential problems, sciatic pain is fairly common.
But watch out – pain is only one diagnostic factor.
Sciatic Diagnosis Indicators Your Doctor Should Take Into Account
There’s one major distinction your doctor has to make to help diagnose the cause of your sciatic problem.
There are many causes of pain spreading down the sciatic nerve. This is the more common type of “sciatica.” Pain, in and of itself, isn’t a very specific indication of what’s going on.
Pain that your brain interprets as coming from the sciatic nerve can happen if there’s a problem with any of the muscles or joints anywhere within the tributary system of the sciatic nerve. Pain could arise from a problem with
- the sacroiliac joint
- the piriformis muscle
- the gluteal muscles
- the hamstrings
- the lateral fascia of the thigh
It’s a long list.
These can be serious, complex problems. But schematically, they share a simple feature: there’s nothing wrong with your sciatic nerve – it’s just picking up and amplifying pain signals from your joints and muscles.
If you fix the imbalance causing sacroiliac strain, piriformis spasm, tightness of the lateral fascia, or whatever, you’ll be good to go.
But there’s another category of sciatic problem that’s more complicated. Some people have pain PLUS loss of nerve function.
Pain Vs. Nerve Dysfunction
Your problem may be more complex – you could have a problem with the sciatic nerve itself. You’ll probably have pain. But you’ll also have loss of normal nerve function.
For instance, you could have
- weakness of some of the muscles of your leg or foot
- diminished knee-jerk reflex action or loss of other, similar reflexes
- diminished sense of touch
To pick up on these signs, your doctor may
- test the strength of various muscles
- tap your knee, ankle or foot with a reflex hammer
- brush your skin with a cotton ball, lightly prick it with a pin, or hold a tuning fork against it to test various aspects of the touch sensation
In some cases (and more commonly when your doctor is a proponent of the diagnostic-overkill theory of medical practice) you may require electrodiagnostic testing.
To perform electrodiagnostic testing, the technician will insert small needles along the course of the sciatic nerve to test electrical nerve conduction from point to point. This type of test can pick up a subtle level of nerve damage than could be missed with the basic in-office tests of skin sensation, reflexes, or muscle strength.
Most Common Cause of Loss of Sciatic Nerve Function
If you have a loss of nerve function (skin sensation, weakness, or altered reflexes) the most common cause is a pinched nerve. And the most common cause of a pinched nerve is a bulging or protruding disc in your low back.
There can be other causes as well. But knowing the true nature of your sciatic condition will help your doctor get to the root of your problem more quickly.
Help Your Doctor Distinguish Sciatic Pain from Loss of Sciatic Function
If you understand this distinction – sciatic pain vs. loss of sciatic function – it will help you get the most out of your doctor’s visits. You’ll be more prepared to help your doctor work through the diagnostic process to find the treatment that’s going to work for you.