Introduction: mastitis, a breastfeeding-related inflammatory condition, presents significant health challenges. YouTube is a popular platform for health information, but its content quality and credibility are inconsistent.Methods: a qualitative content analysis was conducted on 51 YouTube videos about mastitis, selected by relevance, user engagement, and views. The analysis evaluated medical information, credibility, and discursive strategies, using predefined criteria such as technical language, source reliability, and narrative coherence.Results: of the 51 videos analyzed, 98% addressed symptoms (e.g., pain and inflammation), 94 % included definitions, and 82 % discussed causes. Treatment strategies were present in 78%, while only 63 % mentioned preventive measures. Emotional and sociocultural dimensions were overlooked in 86% of videos. Institutional channels achieved higher credibility scores, averaging 3.8/5, while independent creators averaged 2,4/5. Educational and narrative-personal tones dominated, appearing in 39 % and 45 % of videos, respectively. However, 27% contained commercial elements, potentially undermining credibility.Conclusions: youTube shows potential for health education about mastitis but requires stricter content quality standards. Enhancing emotional and sociocultural content through collaboration between health organizations and digital creators could improve the reliability and impact of information shared.