SEO in medical writing is the practice of optimizing health and medical content to rank in search engines while meeting strict accuracy, compliance, and trustworthiness standards. Medical content falls under Google's YMYL category, meaning it faces higher scrutiny for authorship credentials, factual accuracy, and citation quality than most other content types. The core challenge is balancing search visibility with medical integrity. You need to research keywords patients actually use ("knee pain after running" not "patellofemoral syndrome"), structure content for featured snippets, and optimize meta data, but you cannot sacrifice clinical accuracy or oversimplify to the point of misinformation. Every health claim needs credible sourcing, typically peer-reviewed journals or government health agencies like Health Canada or CDC. Google's August 2018 Medic Update and subsequent core updates dramatically raised the bar for medical content. Sites now need demonstrable E-E-A-T: author bios showing medical credentials (MDs, RNs, PharmDs), clear editorial oversight, proper citations, and transparent organizational information. A blog post about diabetes treatment written by an unnamed contributor will almost never outrank content by an endocrinologist with a published author page. Key ranking factors specific to medical SEO include author credentials displayed prominently, citation to authoritative medical sources, regular content updates to reflect current treatment standards, clear distinction between editorial and sponsored content, and schema markup for medical entities. Technical elements matter too: Core Web Vitals, mobile optimization, and security (HTTPS is non-negotiable for health sites). At Ottawa SEO Inc., when we work with medical clients or health-adjacent businesses, we insist on credentialed reviewers for any clinical claims and build author authority pages before publishing. We've seen sites recover from traffic drops by simply adding proper author credentials and citations to existing content. For Canadian healthcare providers, compliance with provincial advertising regulations and PIPEDA for patient data adds another layer beyond pure SEO. The investment in doing medical SEO properly is higher than typical content marketing, but the traffic quality and conversion rates justify it because you're reaching people with urgent, specific health needs.