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
• etc.

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.

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Deepen Your Body of Knowledge

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