I have one and off back pain especially after working long hours or lifting boxes/books. I also wake up with stiffness/slight pain in my lower back occasionally. My husband has noticed a bruise on my lower back over the past few weeks. It is very low and is in a straight vertical line. My lower back also hurts if you push on it.
Hi there, low back pain is one of the most common complain in people who work for long hours especially the on lifting heavy stuff. This could be due to excessive use of back and load being heavy, or due to bad posture while you are doing your job or due to weakness due to any bone pathology. I would advise you to get an MRI done for your back and also your serum calcium and it D levels. If you are premenopausal then osteoporosis is to be kept in mind. If everything is fine then you could visit a physiotherapist and do some back muscle strengthening exercises. He will also be able to guide you as to the proper posture to be adopted while lifting heavy stuff. You could take few painkillers to assuage the pain for the time being, taking care to take them only after a meal and never on empty stomach or with alcoholic Chat Doctor.  Take care.