Rare Disease in the U.S. 2025

Rare disease communities welcomed me as a researcher, inspired me to highlight their ingenuity in my book, Rebel Health, and now I am honored to share results from the first probability-based national survey to measure the rare disease population.

I partnered with my former Pew Research colleague Kristen Purcell, now at SSRS, to write the survey questions and with my ARCHANGELS colleagues, Alexandra Drane, Sarah Stephens-Winnay, and Erin Stolte, to get it into the field. You can read the full report, topline, and press release on the SSRS site, but here are some highlights:

We found that 8% of U.S. adults say they or someone they live with has ever been told by a doctor or other health professional that they have a rare disease (defined as one affecting fewer than 200,000 people in the U.S.).

This finding reinforces a long-held assertion that one in 10 Americans is affected by rare disease. Advocates and experts in the field estimate the number is even higher since more rare diseases are identified and diagnosed each year. Some people may also live with a diagnosis that they do not know is a “rare disease” because their clinician did not tell them their condition is rare. This survey captures a snapshot of those who identify with the term “rare disease” as a measure of awareness. With this data we can further understand how these households interact with health care resources.

An additional 7% of U.S. adults who do not live in rare disease households say they or someone they live with is currently experiencing an illness that doctors or other health care professionals have not been able to diagnose. Together, they represent 15% of U.S. households, nearly 20 million, affected by rare disease or an undiagnosed illness.

People living in rare disease and undiagnosed illness households are from all walks of life and regions of the country.

The survey found that people affected by rare disease or undiagnosed illness are more likely than others to use telehealth options, AI tools to learn about a health condition or treatment options, and to go online to find other people with similar health concerns.

Looking only at survey respondents who reported living in a rare disease household:

• 63% have, in the past year, seen a doctor or other health care provider, such as a specialist, online or via a telehealth appointment, compared with 45% of those not living in a rare disease household.
• 50% have, in the past year, gone online to find other people who might have health concerns similar to their own, compared with 37% of those not living in a rare disease household.
• 38% have, in the past year, used an AI tool such as ChatGPT or Gemini to learn about a health condition or treatment options, compared with 21% of those not living in a rare disease household.
• 29% have, in the past year, seen a mental health professional or therapist online or via a telehealth appointment, compared with 18% of those not living in a rare disease household.
• 28% have, in the past year, seen a mental health professional or therapist in their office or health care clinic, compared with 19% of those not living in a rare disease household.

Since it is particularly challenging for rare disease household members to connect with peers in their offline communities, it is heartening to see that they are likely to be successful when they look online. Of those who tried, eight in ten were successful in finding people who share their same health concerns. 

When it comes to seeing a doctor or other health care provider, such as a specialist, in their office or health care clinic in the past year, eight in ten respondents said yes, whether they live in a rare disease household or not. The only difference was frequency: 19% of those living in rare disease households reported seeing a clinician in person seven or more times in the past year, compared with 9% of non-rare-disease household members.

Methodology: This study was conducted by SSRS on its Opinion Panel Omnibus platform for Susannah Fox and ARCHANGELS, with support from the Association on Aging in New York. The SSRS Opinion Panel Omnibus is a national, twice-per-month, probability-based survey. Data collection was conducted on two waves of the omnibus, from January 17 to January 21, 2025 and from February 7 to February 10, 2025, among a total sample of N = 2,012 respondents. The survey was conducted via web (n = 1,952) and telephone (n = 60) and administered in English (n = 2,012).

Your turn: Do any of the findings surprise you? Which ones resonate with your own experience, whether or not you live with a rare disease? Comments are open.

Image: Zebra, by Andy Lederer on Flickr. Zebras are a symbol for Rare Disease Day (February 28) because of the medical aphorism, “When you hear hoofbeats, think zebras,” because a set of symptoms is likely to be something typical, not rare.