As of this writing, there is no widely used single laboratory test for determining whether a patient has Fibromyalgia, as there is for many other diseases. Diagnosis is usually much more complex and convoluted, and for this reason, many patients who have it can go undiagnosed for years, sometimes even decades. When looking for Fibromyalgia, doctors try to rule out other possible diseases such as various nerve and muscle diseases, arthritis, anemia, etc. which have similar symptoms. Doctors can also look for pain and fatigue, experienced throughout the body. Doctors will also examine the patient's medical history, as well as the family's medical history as there is often the potential for a genetic precursor.