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Home / FAQ / How common is FND?

How common is FND?

The answer to this question depends on what data you look at. As this has been an area that has led to confusion, I’ve laid out some of the studies below. Sorry it’s a bit technical. The bottom line is that FND is one of the commonest conditions in neurology, but it’s been hidden from view, and a lot more people have it than most people realise.

FND has been found to be one of the commonest reasons to see a neurologist.

In Emergency Medicine settings FND is also common.

How many people in the USA or UK have FND?

This is a hard question to answer accurately but an estimate can be made by looking at the two most common types of FND, functional seizures and functional movement disorders (including limb weakness and stroke-like presentations). If the best estimates of those conditions (Duncan et al., 2011)(Villagrán et al., 2021) are put together with studies of children and young people (Hansen et al., 2020) (which don’t appear in the same studies), along with studies that tell us how long, on average people have FND symptoms for, then we end up with a figure of between 250,000-500,000 in the US and around 50-100,000 in the UK. The true number may be less than that, but it also could be a lot more.

Another recent study from general practice (family doctors) covering 72% of people in Scotland found that FND had been diagnosed in 8040 people. That would be equivalent to 11,150 people in Scotland and around 140,000 people in the UK. 

Most neurologists acknowledge that FND is underestimated in clinical services as its often poorly coded by hospital administration systems. In some parts of the world, neurologists don’t receive payment if they use existing codes for FND which reduces estimates (Stone et al., 2014). Better studies would be welcome to gain a more accurate idea of the precise numbers, but it’s clear that it’s a common problem.

In the US a study of costs of FND showed that it was consuming over $1 billion dollars in inpatient costs a year – similar to motor neuron disease/ amyotrophic lateral sclerosis (Stephen et al., 2021).


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