Undiagnosed Day 2026

On April 29, 2026, we mark Undiagnosed Day—this isn’t just a day, it’s a movement, a day not about the disease, to create awareness and action for People Living With Undiagnosed Diseases (PLWUD). There are too many people living with questions that remain unanswered.

This day is dedicated to the 350 million People Living With Undiagnosed Diseases (PLWUD) and their families but also for the clinicians, researchers, genetic counsellors and patient organizations working tirelessly to find answers.

This Year we are in Gdańsk, Poland

On April 29–30, 2026, Undiagnosed Day will be marked in Gdańsk, Poland with a two-day international event focused on improving diagnosis for children and adults living with undiagnosed conditions. 

Organized by Wilhelm Foundation, ERDERA, Medical University of Gdańsk (GUMed), and the University Clinical Centre in Gdańsk (UCK), the meeting will bring together clinicians, clinical geneticists, researchers, and invited experts to strengthen phenotype-led diagnosis through collaboration, shared learning, and practical exchange. 

April 29 is a closed phenotyping roundtable where children living with undiagnosed diseases and their families meet directly with specialists, with the hope that—through this collaboration—some families will receive a diagnosis. Inspired by the global spirit of the Undiagnosed Hackathon, this meeting centres on clinical assessment, practical decision-making, and direct engagement with individuals and families. 

The second day (April 30) is an open, in-person conference bringing together clinicians, researchers, and the wider undiagnosed disease community.

The programme focuses on practical, real-world approaches to diagnosis and care—combining expert talks with case-based discussions to explore what enables a diagnosis, what still prevents answers, and how we move forward when no diagnosis is found.

Through sessions on modern diagnostics, clinical cases, diagnosis-agnostic care, and international collaboration, participants will gain insights into how phenotyping, advanced genomics, and global data sharing are reshaping the diagnostic pathway for people living with undiagnosed diseases.

The day is designed to be interactive and actionable—sharing knowledge, strengthening collaboration, and accelerating progress toward answers for PLWUD. 

Let’s Make Our Voices Heard

Be part of the change, there are many ways that you can get involved to make a pledge, spread the word, and share a story to raise awareness and support. 

Your voice matters. Together we can raise awareness, inspire collaboration, and bring visibility to the 350 million People Living With Undiagnosed Diseases PLWUD worldwide. Are you a clinician, researcher, representative of a patient organization, advocate, or healthcare professional working to solve undiagnosed diseases?

Join us and help shine a light on the global challenge of undiagnosed diseases.

Ready to raise your voice?

👉 Send your 2–3 minute video in English via WeTransfer to undiagnosedday@wilhelmfoundation.org before April 25.

🩺 2. Clinicians: Join the Global Effort

Your work matters. Let it be counted.

If you're seeing a child or adult with an undiagnosed disease on April 29, let us know. 


Together, We Are a Global Force
 

By taking part, you’ll gain:

Access to a toolkit of social media materials Visibility as part of a global awareness movement A platform to show solidarity with the 350 million PLWUD around the world

Let’s make Undiagnosed Day a moment the world can’t ignore.
Let’s illuminate the world for those still searching for answers.

Let’s make April 29 a turning point.

#UndiagnosedDay2026

Make the pledge. Spread the word. Share a story.