A rare disease is one that affects fewer than 200,000 people in the United States. There are nearly 7,000 rare diseases. More than 25 million Americans have one.

Rare diseases

• May involve chronic illness, disability, and often premature death
• Often have no treatment or not very effective treatment
• Are frequently not diagnosed correctly
• Are often very complex
• Are often caused by changes in genes

It can be hard to find a specialist who knows how to treat your rare disease. Disease advocacy groups, rare disease organizations, and genetics clinics may help you to find one.

NIH: National Institutes of Health