Interpretations of Menstrual Blood Appearance and Diagnostic Potential Among Social Media Users: Cross-Sectional Mixed Methods Social Media Listening Study.

Background: Menstruation has long been framed primarily as a hygiene issue, with mainstream products and public messaging emphasizing concealment and disposal of menstrual blood (MB). This has contributed to a culture of silence in which conversations about menstrual health have been marginalized in public and clinical settings. Recent international guidance, including the World Health Organization's call to reframe menstruation as a health issue, underscores the need for more open discourse. Simultaneously, social media has become a prominent space where menstruating individuals share experiences, seek advice, and challenge stigma. The resurgence of reusable menstrual products has increased users' direct observation of MB, prompting questions about variations in color, texture, and smell. These developments highlight growing curiosity about MB yet reveal persistent information gaps regarding how MB is understood outside the clinical setting. Objective: This study aimed to examine how MB is represented in social media discourse and to explore individuals' perceptions of MB's potential use as a diagnostic tool. Methods: We conducted a cross-sectional, convergent mixed methods social listening study combining qualitative content analysis, social network analysis, sentiment analysis, and descriptive statistical analysis. Data were collected from TikTok (ByteDance), Facebook (Meta), Instagram (Meta), and Reddit using Mention and Apify. Between February 1 and 28, 2025, 6263 posts and videos were extracted using 3 strategies-group searches, hashtag searches, and social listening alerts. All data were anonymized, and demographic information was unavailable. After removing duplicates, non-English content, images, and posts without reference to blood, 349 posts were included. Coding followed a multistep deductive process in Atlas.ti. All posts were assigned with quotations, which were designated with one or more codes. Network analysis examined associations between appearance descriptors and reported health conditions. Sentiment analysis assessed perceptions of MB-based diagnostics. Results: Among the included posts (n=349), most originated from Reddit and Facebook. Seeking help (154/349, 44.1%) was the most common type of post. Appearance descriptions (n=243 posts) focused on color, particularly brown, bright red, pink, and black; consistency, particularly coagulation; and smell, mainly unpleasant. Network analysis linked specific colors and textures to perceived conditions, including miscarriage, endometriosis, hormonal changes, polycystic ovary syndrome (PCOS), and infections. Discussion of MB as a diagnostic tool (n=80 posts) was less frequent but included predominantly positive quotations (110/115, 95.7%), emphasizing accessibility, noninvasiveness, and home-based sampling. Concerns (19/115, 16.5%) focused on inclusivity, stigma, and bodily autonomy. Conclusions: This study demonstrates that social media serves as an important source for discussion on MB-related topics and highlights a gap between public information needs and the available scientific evidence. The findings also indicate a strong interest in MB characteristics and support further research into its diagnostic potential. To our knowledge, this is the first study to analyze social media discussions on MB characteristics and its diagnostic potential.