A diagnosis of arthritis can change your life in many ways, but don't accept that news too quickly. It is surprisingly common for arthritis to be misdiagnosed, and even if you do have arthritis the doctor may specify the wrong type.

In an analysis of 583 doctor-reported errors from 22 hospitals across the United States., which was published in the November 9, 2009, issue of the Archives of Internal Medicine, Gordon D. Schiff, MD, of Brigham and Women’s Hospital in Boston and his co-authors found that diagnostic errors were most common in the testing phase. In fact, doctors failed to order, report or follow up on lab results an astounding 44 percent of the time.

Any time a doctor orders a lab test, X-ray, MRI or ultrasound, ask when you can expect to learn the results. If you don’t hear from the doctor’s office in a timely manner, call until you find out what the test determined. If the results raise concerns, make sure you are scheduled to see the doctor again for a follow-up appointment.

Many rheumatic diseases have symptoms that overlap, and blood tests are rarely conclusive. Doctors often arrive at these diagnoses by ruling out many other possibilities first. While there are no data to show which rheumatic diseases are most commonly misdiagnosed, here are some that are well-known for being tricky to detect:.

Sjögren’s Syndrome

This is an autoimmune disease that attacks the body’s moisture-producing glands. The most distinctive features of Sjögren’s syndrome are dry eyes and dry mouth, but this condition can affect the entire body, damaging organs such as the liver, lungs, kidneys and stomach. According to the Sjögren’s Syndrome Foundation, on average, it takes patients up to seven years to receive a diagnosis of Sjögren’s.

Sjögren’s Syndrome often is mistaken for fibromyalgia, chronic fatigue syndrome, allergic conjunctivitis (eye allergies), medication side effects, blepharitis (inflammation of the eyelash follicles), and xerophthalmia (dry eyes caused by decreased tear production).

Lupus

A disease in which the body attacks its own joints, skin, tendons and vital organs, lupus is episodic, meaning that symptoms will flare and then disappear. Doctors have dubbed lupus “The Great Imitator” because of its ability to look like so many other diseases.

Lupus is often mistaken for rheumatoid arthritis (RA), scleroderma, rosacea, multiple sclerosis, Lyme disease, depression, vasculitis, myositis (inflammation of muscle tissue), endocarditis (inflammation of the sac around the heart), fibromyalgia, and meningitis.

Fibromyalgia

This is a clinical syndrome characterized by a mix of symptoms which may include persistent, widespread pain, muscle spasms, mood disturbance, fatigue, insomnia, problems with memory and concentration and irritable bowel syndrome

Fibromyalgia often is mistaken for RA, osteoarthritis (OA), Lyme disease, chronic fatigue syndrome, hypothyroidism, depression, lupus, neuropathy, sciatica, and anemia.

In many rheumatic diseases, symptoms develop gradually, and the full clinical picture can only be appreciated over time. Here are the average amounts of time it takes doctors to make a diagnosis from the time symptoms first appear:

Rheumatoid arthritis: 6 to 9 months
Juvenile arthritis: 5 months
Fibromyalgia: 2 to 5 years
Sjögren’s syndrome: 3 to 7 years
Ankylosing spondylitis: 6 to 9 years