What Causes Sweating, Headache, Nausea And Tiredness After Facet Joint Injection?

I had facet joint injections last Monday and have been taking painkillers up untill Saturday Night. Yesterday I felt hot and sweaty, had a headache, bit nauseous and extreemly tired, and this has carried on today as well. Are there any recommendations as to what this could be or should I really visit my local doctor?