It’s my understanding that physical therapy and physiotherapy are the same thing, but physical therapy is the term more used in the American English while physiotherapy is used more in the UK and Australia.

It’s kind of like how in the US we use the term “primary care physician” more often whereas in other English-speaking countries. the term “general practitioner” or GP is used.

In my experience, a PT can do a lot without a definite diagnosis and can do an assessment of their own to try to determine how the nerves, muscles, bones, etc. may be contributing to your pain, as their focus is more on function and helping you feel better, but I suppose it depends on the PT. This can be helpful because some diagnoses don’t have definitive proof. Or with imaging, pain level doesn’t necessarily correlate to changes seen on imaging and vice versa.

Have you tried seeing a physiatrist if you wanted more clarification on what’s causing your pain? They’re internists but also specialize in physical medicine and rehabilitation so tend to look at things more holistically. I have chronic pain, and my physiatrist has been extremely helpful and was instrumental in helping me get diagnosed.