Anxiety, difficulty sleeping, fatigue and rapid heartbeat...is it stress or overactive thyroid symptoms? 

When the thyroid is out of whack, it affects the whole body. The thyroid gland may overproduce or underproduce hormones, and both conditions cause a host of sometimes-vague symptoms. But how do you know if you have hyperthyroidism, or overactive thyroid? Knowing the signs and symptoms of an overactive thyroid is the first step to get help and prevent more serious problems associated with the untreated condition. 

Function of the Thyroid Gland 

The thyroid is a butterfly-shaped gland located in the throat. It produces and secretes a hormone that regulates how the body uses energy -- its metabolism -- so any problems can affect all areas of the body. When the gland produces too little or too much of the hormone, it can cause a host of problematic symptoms. Only a doctor can tell you if your symptoms point to an overactive thyroid, so make an appointment for an examination and tests to get to the bottom of the problem.