NMOSD is a rare and debilitating autoimmune disease caused by inflammation in the central nervous system (the optic nerve, brain stem and spinal cord). If not treated, this inflammation can cause repeat attacks and permanent disability, such as blindness and paralysis.

NMOSD can be difficult to diagnose and is often mistaken for multiple sclerosis (MS)—in fact, four out of 10 of those living with NMOSD report being initially misdiagnosed with MS.

~16,000 to 17,000

people in the United States live with NMOSD. There is an unstoppable community out there and power in learning from one another.

Differences Between NMOSD and MS 

A blood test for AQP4-IgG can confirm that you have NMOSD. If antibodies against aquaporin-4 (AQP4) are found in your blood, it will confirm you have NMOSD and not MS. AQP4 antibodies are present in up to 80% of people with NMOSD, so testing for this antibody is essential to receiving a diagnosis.

While NMOSD and MS can impact the body in similar ways, there are several factors that differentiate the diseases:


  • A single attack can cause disability
  • Attacks are usually more severe and can result in permanent disability
  • AQP4 antibody positive in a blood test


  • Several individual attacks typically cause disability over time
  • Attacks are typically less severe and can result in better recovery
  • AQP4 antibody negative in a blood test

Partnering with a specialist can help ensure the right diagnosis and disease management.

Find a specialist near you with the specialist finder tool

Ireland, a young woman living with NMOSD is looking compassionate and reaching across a table to hold hands with another woman, Kim, who also lives with NMOSD.

Hear the Unstoppable Stories 
of Those Living With NMOSD and Their Care Partners

Learn from the inspiring stories of real people who live with NMOSD, like Christine, and their care partners.

Learn more

Find Resources for Living

Access digital resources and educational tools, learn strategies for self-advocacy and connect with NMOSD advocacy groups.

Learn more