Lyme disease is very commonly misdiagnosed as Fibromyalgia, Chronic Fatigue Syndrome, ALS, Lupus, MS, Rheumatoid Arthritis or other unrelated illness. Be sure to check the lyme symptoms list and if you have any doubt, get tested! And be sure it is done by a reputable lab such as IGeneX. When I was very sick with Lyme and co-infections, I tested negative with a regular lab. Fortunately someone told me to repeat the test with IGeneX. http://igenex.com/Website/ Many people are suffering needlessly because doctors do not realize the high percentage of false negatives with Lyme tests ordered from ordinary labs.