Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

Which condition is often diagnosed by exclusion?

1. Osteoarthritis

2. Rheumatoid Arthritis

3. Fibromyalgia

4. Cronic Fatigue Syndrome

The correct answer is: Fibromyalgia

Fibromyalgia is typically diagnosed by exclusion because there are no definitive laboratory tests or imaging studies that can confirm the condition. Instead, the diagnosis is made based on the patient's reported symptoms and the exclusion of other possible causes of those symptoms. Patients with fibromyalgia commonly experience widespread musculoskeletal pain, fatigue, sleep disturbances, and cognitive difficulties, which can overlap with a variety of other conditions. Consequently, physicians often need to rule out other diagnoses, such as rheumatoid arthritis, osteoarthritis, or other forms of inflammatory arthritis, to arrive at a diagnosis of fibromyalgia. In contrast, conditions like osteoarthritis and rheumatoid arthritis have clear diagnostic criteria and can often be confirmed through specific tests, such as imaging studies or laboratory markers of inflammation. Chronic fatigue syndrome, although also a diagnosis of exclusion, is less commonly emphasized than fibromyalgia in clinical practice due to its more defined criteria and the focus of ongoing research.