If i'm suffering severe lower left back pain and had blood work a few days ago, would kidney problems have shown?

Test for kidneys: It depends on what kind of blood work you had. A renal function test evaluates kidneys, a CBC shows white count which may be elevated during an infection. If you believe you have kidney stone, see a urologist. If you have fever, you could have infection going on. Increased urination, flank pain, blood in urine, burning may all be due to kidney or bladder issues.