What Causes Soreness In Calf Muscles?

I am Andy I am a male and 26 years old.My calfs have been slightly sore the last few months. its not unbearable pain or anything i walk around just fine, its more annoying than anything. recently (just a couple days ago) my left arm has felt sore too dont know if its related or if it ill pass just thought i would mention it. any thought?
-Andy-