Recently, my back always feels sore and my urine is a little yellow.

Back pain : Back soreness can be related to a spinal problem or a referral from an organ. Back pain can come from a urinary tract infection, prostate problem. Depending on which part, back sore can also be from the pancreas, heart, gall bladder, stomach, colon, lung lesions like pneumonia. Urine can normally be yellow. More information is needed you should see your primary care doctor