Sciatica refers to back pain caused by a problem with the sciatic nerve. This is a large nerve that runs from the lower back down the back of each leg.BackPainSlideshowsSciaticareferstobackpaincausedbyaproblemwiththesciaticnerve.Thisisalargenervethatrunsfromthelowerbackdownthebackofeachleg.Whensomethinginjuresorputspressureonthesciaticnerve,itcancausepaininthelowerbackthatspreadstothehip,buttocks,andleg.Upto90%ofpeoplerecoverfromsciaticawithoutsurgery.Themostcommonsymptomofsciaticaislowerbackpainthatextendsthroughthehipandbuttockanddownoneleg.Thepainusuallyaffectsonlyonelegandmaygetworsewhenyousit,cough,orsneeze.Thelegmayalsofeelnumb,weak,ortinglyattimes.Thesymptomsofsciaticatendtoappearsuddenlyandcanlastfordaysorweeks.Upto85%ofAmericansexperiencesometypeofbackpainduringtheirlives.Butthisdoesn'talwaysinvolvethesciaticnerve.Inmanycases,backpainistheresultofoverextendingorstrainingthemusclesinthelowerback.Whatmostoftensetssciaticaapartisthewaythepainradiatesdownthelegandintothefoot.Itmayfeellikeabadlegcrampthatlastsfordays.Mostpeoplewhogetsciaticaarebetweentheagesof30and50.Womenmaybemorelikelytodeveloptheproblemduringpregnancybecauseofpressureonthesciaticnervefromthedevelopinguterus.Othercausesincludeaherniateddiskanddegenerativearthritisofthespine.Themostcommoncauseofsciaticaisaherniateddisk.Disksactlikecushionsbetweenthevertebraeofyourspine.Thesedisksgetweakerasyouageandbecomemorevulnerabletoinjury.Sometimesthegel-likecenterofadiskpushesthroughitsouterliningandpressesontherootsofthesciaticnerve.About1in50peoplewillgetaherniateddiskatsomepointinlife.Uptoaquarterofthemwillhavesymptomsthatlastmorethan6weeks.Naturalwearandtearofthevertebraecanleadtoanarrowingofthespinalcanal.Thisnarrowing,calledspinalstenosis,mayputpressureontherootsofthesciaticnerve.Spinalstenosisismorecommoninadultsoverage60.Inrarecases,sciaticamayresultfromtumorsgrowinginsideoralongthespinalcordorsciaticnerve.Asatumorgrows,itmayputpressureonthenervesthatbranchofffromthespinalcord.Thepiriformisisamusc