bunion bun·ion (bŭn'yən)
A localized swelling at either the medial or dorsal aspect of the first joint of the big toe, caused by an inflamed bursa.
type of bursitis that appears as a bulge covered by thickened skin occurring at the base of the big toe, where friction against the side of the shoe takes place. The protuberance is due to a swelling of the bursa mucosa, a closed sac filled with a clear, lubricating fluid. The bunion causes pain, localized tenderness, and limitation of motion, and it results in permanent deformation, forcing the toe toward the little toe.
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