Muscles very sore, particularly arms, unrelated to exercise. tired. lack energy. what could be some causes?

There are many: Possibilities, but if you were my patient, given your gender and your age the first thing that i would check for is polymyalgia rheumatica. The test is a simple blood test called an erythrocyte sedimentation rate. Please see your family doctor for a definitive work-up.

Sore muscles: Myalgia.Sore muscles or inflammation of muscles. May be medication related - trazadone dehydration, electrolyte imbalance - calcium and magnesium. May be the trazadone, but be sure to check with your dr before you stop the medication.