Rare and undiagnosed diseases
A rare disease is a disease that affects fewer than 1 in 2,000 people. A person with an undiagnosed disease usually has rare disease symptoms. Someone with an undiagnosed disease might still be looking for a diagnosis. Sometimes a diagnostic test is not available for their condition.
Rare and undiagnosed diseases are individually rare but collectively common. They affect one in 12 people in Australia. This adds up to approximately 63 000 children in Western Australia.
People living with rare or undiagnosed diseases face many challenges. The journey to rare disease diagnosis is often:
- long
- involves many specialists
- can include many incorrect diagnoses.
These conditions are severe, chronic, and often disabling and life limiting. They can affect all aspects of life. Only 5 per cent of rare diseases have a treatment option.
Patients must navigate many complex sectors, such as health, education or disability. Often, people with a rare or undiagnosed disease experience isolation, stigma, and discrimination. This can be challenging and bring up a range of emotions, like loneliness, anger or grief.
You are not alone in your experience. There are support groups available for people with rare and undiagnosed diseases. Emotional support is available.
Rare Care Centre
Rare Care Centre launched in 2022. Rare Care Centre helps with the challenges of living with a rare or undiagnosed disease. It can provide support to children and their families. Find out more information about the Rare Care Centre, including information about referral criteria and pathways.
Last reviewed: 25-08-2026
Acknowledgements
Office of Population Health Genomics
This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.