Fatigue is caused by a wide variety of conditions.  While rheumatic conditions can cause fatigue, they are not the only conditions that do so.  Reviewing with your family doctor if you have any other symptoms can help narrow down the cause of the fatigue to ensure you manage it appropriately.  If your family doctor finds other symptoms that could be related to rheumatic diseases, then it would be appropriate to see a rheumatologist to determine if this is the case.