FND is estimated to affect 50,000-100,000 people in the UK.
It limits the brain and nervous system’s ability to send and receive signals.
Its underlying cause is not known, but some experts think it could be linked to stress, trauma or a response to a virus or other inflammatory condition.
Mark Edwards, professor of neurology and interface disorders at King’s College London, says it causes “significant disability” and can have a similar impact to conditions such as Parkinson’s and multiple sclerosis.
For Hannah, it has proved absolutely debilitating.
“I have a lot of fatigue and my speech isn’t great. I have seizures, paralysis, loss of mobility, gait problems, breathing problems, limb weakness and brain fog,” she said.
“I can’t walk unaided. I can probably do six steps before I’m out of breath, so I’m in a wheelchair and heavily reliant on people to help me.”