A kidney infection (also known as pyelonephritis) can be a very serious illness. It usually begins with a urinary tract infection
that starts in the bladder. The initial symptoms can be burning when you urinate, pain in the lower abdomen, fever, and generally not feeling very well. If the urinary tract infection goes untreated, it can move up into the kidneys in the opposite direction of the urine flow. When this happens there is a risk of damage to the kidneys and a greater risk that the infection will move into the blood stream. One of the symptoms of a kidney infection is lower back pain often both sides but sometimes just one. A very common sign is pain when the back is touched. I will say that without any other signs of an infection (fever, burning with urination), the chances that it is a kidney infection are lower. There are many other reasons other than a kidney infection that the lower back would hurt. Only your doctor
can tell the difference between them.
I suggest that you schedule an appointment with your primary care physician
. He or she can examine your back and abdomen as wells obtain a urine sample for testing. Your doctor will be able to tell right then and there if a kidney infection is the cause of your back pain.