People Living With Undiagnosed Diseases PLWUD
People Living With Undiagnosed Diseases (PLWUD) are children and adults who live with unexplained, ongoing health conditions, without a diagnosis, a clear explanation, or a defined path forward. An undiagnosed disease is not the absence of illness; it is the absence of answers.
Worldwide, an estimated 350 million People Living With Undiagnosed Diseases PLWUD. Around 70% of PLWUD are children. Despite major advances in genomic medicine, only about 40% of individuals undergoing advanced testing receive a diagnosis. For the remaining 60%, the diagnostic odyssey does not end - it continues, often for years or even a lifetime.
Living without a diagnosis affects every aspect of life. Without a disease name, families face uncertainty about prognosis, treatment options, emergency care, and genetic counselling. Parents may be told their child’s condition is “unlikely to be hereditary,” only to see more than one child in the same family affected. PLWUD may struggle to access appropriate care, social support, or recognition of their symptoms.
For PLWUD and their families, a diagnosis means more than a label. It can:
- Guide the right medical care and follow-up
- Prevent complications and, in some cases, save lives
- End years of uncertainty and validate lived experiences
- Enable informed family planning and genetic advice
- Connect families to specialists, research, and peer support
Even when no cure exists, knowing what you are dealing with changes everything.
The Wilhelm Foundation exists for the millions still waiting. We work to shorten—and ultimately end—the diagnostic odyssey by driving collaboration, innovation, and global action so that no child or adult is left without answers.
PLWUD are not rare in number. They are rare in recognition. That must change.