What is the required number of tender points to diagnose fibromyalgia?

In the diagnosis of fibromyalgia, it is necessary to have tenderness in a specific number of tender points as part of the established criteria. The correct number required to meet the diagnostic criteria is 11 out of 18 tender points.

The concept of tender points was outlined in the American College of Rheumatology (ACR) criteria developed in the early 1990s, which emphasized the presence of widespread pain and tenderness in these specific locations. The diagnosis is supported by the presence of pain in combination with associated symptoms such as fatigue, sleep disturbances, and cognitive difficulties, known collectively as fibromyalgia syndrome.

The reason the requirement is set at 11 tender points instead of a lower number is to ensure a degree of specificity in diagnosis, helping differentiate fibromyalgia from other conditions that may present with similar symptoms but do not involve the same pattern of localized tenderness. This specificity is crucial for providing accurate treatment and managing the condition effectively.