Transgender and gender-diverse (TGD) adolescents experience limited access to gender-affirming care (GAC) and information and use social media platforms for informational and social support. We conducted conventional content analysis of posts on the platform, Tumblr and applied univariate statistics to characterize health and wellness themes represented by this content. Content was predominantly transmasculine-relevant. Posts addressing the trans health care paradigm often co-occurred with content referencing affirmation logs, the physical and emotional impact of affirmation, surgery, and unspecified medical interventions. Gender-affirming hormone therapy was the most prevalent intervention referenced in posts related to non-professional/non-licensed medical care and advice requests. Transgender and gender-diverse youth-serving individuals can use this information to mitigate harm, enhance patient education, and improve the overall well-being of TGD youth. Further research is needed to characterize the effect of content encountered on social media on pediatric patient experiences and on outcomes of GAC.