Hello, what is the pattern of the ache?
When does it occur?
How long does it last?
Where do you feel the pain/ache?
Any numbness or tingling in fingers?
Thanks for the extra information. Having pain in the muscles is 'myalgia' which is not arthritis (joint pain) but can be just as wearing.
The first thing is to establish if this is a side effect of medication such as a statin (simvastatin, atorvastatin etc) as this can be stopped. The next thing is to have blood test to look at inflammatory markers (ESR, PV) to see if there is an inflammatory problems such as Polymyalgia Rheumatica which is easily treated with oral steroids.
If these are normal then full blood count, electrolytes etc need to be checked for electrolyte deficiencies or signs of muscle damage (creatine kinase) and this may need referral to a rheumatologist for a proper assessment.
So step one is to see your family doctor for an examination and some basic tests.