Intermittent hydrarthrosis, unspecified site

This code describes a recurrent, non-inflammatory effusion into a joint, characterized by episodes of swelling and fluid accumulation that resolve spontaneously. The underlying cause is often unknown, and the condition typically affects large joints, though this specific code indicates an unspecified location.

Use this code when documentation clearly states "intermittent hydrarthrosis" without specifying a particular joint. This diagnosis is supported by physician notes detailing recurrent, self-limiting joint swelling without signs of infection or systemic inflammatory disease.

• Avoid using this code if a specific joint is documented; instead, use a more precise code from the M12.4 subcategory (e.g., M12.41- for shoulder).
• Ensure documentation differentiates intermittent hydrarthrosis from other forms of arthropathy or synovitis.
• Consider co-reporting with codes for associated symptoms if they are distinct and require separate management.