It's that time of year again

Well I was up bright and early for work but then decided against it and phoned in sick. As the night before I felt my back go into spasms. it did this a few weeks ago and I soldiered on living on pain killers for about a week. I have decided to rest it this time but it's so frustrating when you want to do things. Every time I have had this in the past I thought it was siacitia but on talking to someone they said it wasn't, I thought it was strange when everyone said with siacitia you had pains down your leg and I never got them.