Having a high blood pressure puts you at a greater risk for kidney disease. You have to get your blood pressure into a normal range. Lisinopril should suffice.
To answer your question, this is how you can tell the difference between a kidney pain and back (muscle) pain:
Your back pain could be kidney-related if it is in the small of your back, just below the ribs and not aggravated by movement (e.g. if the pain worsens when you move - it is back or muscle pain).
As with high blood pressure, there are few or no symptoms in kidney disease. Sometimes the symptoms do not occur until there's considerable damage or renal failure. For this reason, it is also called a silent killer.
If symptoms of kidney disease are present, it could be any one or several of the following:
High blood pressure
puffiness around the eyes, swelling of hands and/or feet
back pain (as described above)
loss of weight and/or appetite
visible changes in urine-bloody, cloudy or tea colored, excessive foaming
passing urine less often but more often at night
passing urine with difficulties
protein in urine
Because you already have high blood pressure AND are on medication, your kidney function should be tested at least once a year. The only way to determine the presence of protein in the urine is by having the urine tested.