Just today I began to notice an aching pain in the left side of my lower back. Normally I would have ruled it out as poor form at the gym or something, however, I began experiencing a simultaneous ache in my eft testicle. I don't know if they're related and I will be going to see a doctor on Monday but with the information given, what are some possible causes?
It is not uncommon for back pain to go along with testicular pain, called referred pain. It can be muscular. But, one very common reason for this is a kidney stone. However, disorders within the abdomen, such as a hernia can also cause it. Unfortunately, there are many causes.
If the pain persists or gets worse, especially if it is associated with other symptoms (ie fever, malasie, nausea, blood in urine, etc) then you should see your physician.