Undiagnosed Day was originally founded by a mother in the USA about ten years ago, after her child remained without a diagnosis. Her goal was to raise awareness of the many children afected by undiagnosed diseases.

In 2022, after eight years of marking Undiagnosed Children’s Day, the Wilhelm Foundation recognised the need for greater inclusivity. Since approximately 30% of undiagnosed diseases affect adults, the name was changed to simply Undiagnosed Day.

Today, an estimated 350 million people worldwide live with an undiagnosed disease (PLWUD). Genome sequencing offers answers for around 40% of these individuals — but that still leaves 60% without a diagnosis.
 

Undiagnosed Day 2025

On April 29, 2025, 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 without a diagnosis. There are too many people living with questions that remain unanswered.

This day is for the 350 million Person Living with an Undiagnosed Disease (PLWUD) and their families, clinicians, researchers, genetic counsellors and patient organizations working tirelessly to find answers.

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. 
 

Let’s Make Our Voices Heard

We invite you—whether you are a person living with an undiagnosed disease, family member to a PLWUD, caregiver, clinician, patient organization, researcher, or advocate—to stand with us in two powerful ways:
 

🎥 1. Submit a 1–2 Minute Video

Be seen. Be heard. Be part of the movement.

Are you a physician working in rare diseases or someone living with an undiagnosed disease, or supporting someone who is? Grab your phone or camera and record a short video from your clinic, home, lab, or organization. Share:

• 💬 A word of encouragement
• 🔬 A highlight of your work or research
• 🌍 A message from your country or region
• 📖 Your story or diagnostic journey

Each video becomes part of a global chorus of hope and action — showing the world that PLWUD are not invisible.

✅ Ready to raise your voice?

👉 Register here and send us your video with wetransfer to undiagnosedday@wilhelmfoundation.org: For individuals, families, organizations, healthcare providers, and all allies.

🩺 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. Whether or not you present a case, your participation helps put PLWUD on the global health agenda.

🌐 Bonus: Join the Global Virtual Roundtable on April 30 — a unique opportunity to briefly share a case (with consent) and connect with clinicians worldwide.

✅ Clinicians, make your mark:
👉 Register your participation here


📣 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.

#UndiagnosedDay2025
Make the pledge. Spread the word. Share a story.
 

The golden standard for children and adults with Undiagnosed diseases is to be evaluated at an Undiagnosed Diseases Program (UDP). 

The Undiagnosed Diseases Programs are spread all over the world and collaborate in the Undiagnosed Diseases Network International (UDNI). Read more about International Undiagnosed Diseases Programs (UDPs)