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FND Connect CIC

Can FND Cause Pain? Chronic Pain, Flare-Ups and What Can Help

Pain is common alongside Functional Neurological Disorder, and it can be every bit as real and disabling as weakness, tremor or seizures. But that does not mean every new pain should be labelled “just FND”.

By Matthew G. Pain and daily living
A woman sitting at home in soft daylight, gently holding her forearm beside a heat pack, notebook and glass of water
Persistent pain can sit beside FND, feed into symptom flares and deserve its own assessment and treatment plan.

Quick answer

Pain is very common in people with FND, but the relationship is not one simple cause-and-effect story. Pain may come from another condition, an injury, muscle overwork or guarding, changes in movement, a persistent pain condition, or a mixture of these. Sometimes the pain and FND appear to share nervous-system mechanisms. The useful question is not “is it physical or FND?” It is “what type of pain might this be, what has changed, and what support fits?”

A 2024 systematic review and meta-analysis in the Journal of Neurology, Neurosurgery & Psychiatry pooled 30 different FND cohorts and estimated that 55% of participants reported pain. The estimate came with a wide range between studies, so it should not be read as an exact figure for every person or every FND service. It does show that pain is not a rare side note.

The same review found an awkward but important gap: treatment that improves someone’s movement, seizures or general function does not automatically improve their pain. Pain often needs to be named and treated as a problem in its own right.

Do not let “FND” end the assessment

Having FND does not protect you from arthritis, migraine, infection, nerve injury, endometriosis, inflammatory illness, a fracture, medication side effects or any other cause of pain. It is also possible to have more than one type of pain at once.

NICE guideline NG193 asks clinicians to assess all chronic pain before deciding whether it is chronic primary pain, chronic secondary pain, or a combination. In plain English:

  • Secondary pain is linked to an underlying condition, injury or disease that needs appropriate treatment.
  • Primary pain is persistent pain where there is no clear underlying cause, or where the pain and its impact are greater than would be expected from observable injury or disease.
  • Mixed pain means both can be present. A painful joint, for example, can exist alongside a nervous system that has become more sensitive over time.

These labels are clinical tools, not judgements about whether pain is genuine. Pain is an experience produced by the nervous system; that makes it biological and real, whether or not a scan shows the whole explanation.

Get medical help for a new or different pattern

Seek urgent help if pain is sudden, severe, rapidly worsening, follows a significant injury, comes with chest pain, breathing difficulty, new weakness or numbness, fever or serious illness, or is very different from your usual pattern. Use NHS 111 for urgent advice in England, or call 999 for an emergency. Our FND flare or medical emergency guide can help you make a safety plan, but it cannot diagnose pain.

Why can FND and persistent pain overlap?

There is no single mechanism that explains everybody’s pain. Several things can overlap:

  • Movement and muscle load: tremor, dystonia, altered walking, weakness, bracing or repeatedly catching a fall can leave muscles and joints sore.
  • Reduced or changed activity: long periods of guarding or inactivity can reduce strength and confidence, while sudden attempts to “catch up” can trigger a boom-and-bust flare.
  • Persistent pain processing: pain pathways can become more protective and sensitive. That does not mean the pain is imagined; it means the alarm system can continue to fire even when ongoing tissue damage is not the whole explanation.
  • Another condition: migraine, fibromyalgia, complex regional pain syndrome, joint problems and other diagnoses may coexist with FND and require their own plan.
  • Total nervous-system load: poor sleep, sensory overload, fear, stress, illness and pain can all compete for limited capacity. For some people, more pain coincides with worse fatigue, brain fog, tremor or functional seizures.

“The nervous system is involved” is not the same as “it is all psychological”. Thoughts, emotions, sleep, movement, inflammation, past injury, current circumstances and expectations can all affect pain. None of them makes the symptom voluntary.

What to take to an appointment

You do not need a perfect pain diary. A short pattern is usually more useful than pages of numbers. Try noting:

  • where the pain is and whether it travels
  • when it began and whether the onset was sudden or gradual
  • what it feels like: aching, burning, electric, cramping, pressure or tenderness
  • what makes it better or worse, including movement, rest, sleep and position
  • swelling, colour or temperature change, weakness, numbness, fever or injury
  • how it affects walking, sleep, washing, work, concentration and relationships
  • what medication or strategies you have tried, including benefit and side effects

A useful opening sentence is: “I know I have FND, but this pain is new or has changed. Please help me understand what has been assessed, what type of pain you think this is, and what the follow-up plan is.”

A practical pain flare plan

A flare plan is not a promise that you can control pain. It is a way to reduce last-minute decisions when thinking is already difficult.

  1. Check the safety boundary. Is this your recognised pattern, or is something new, severe or medically concerning?
  2. Reduce avoidable load. Move to a quieter space, loosen an unrealistic schedule and ask for practical help early.
  3. Use agreed treatment. Take medication only as prescribed and use heat, cold, positioning or movement strategies that your clinician has said are safe for you.
  4. Avoid the all-or-nothing trap. Complete bed rest may make some persistent pain patterns harder, while forcing through can deepen the flare. Aim for the level of gentle movement and rest agreed in your plan.
  5. Choose one next review point. Decide when you will reassess and who to contact if the flare is not settling. This stops constant symptom checking without ignoring deterioration.

If activity tends to cost you several days, our FND pacing guide and symptom hangover guide can help you plan around delayed recovery rather than only the pain you feel in the moment.

What can help longer term?

The best plan depends on the pain diagnosis and your goals. It may combine several kinds of support:

  • Medical assessment and treatment for any specific condition, injury or inflammatory cause.
  • FND-aware physiotherapy that understands functional movement symptoms, while also adapting for pain rather than treating pain as a test of motivation.
  • Occupational therapy for activity, sleep, equipment, routines, sensory load and practical participation. FND occupational therapy consensus recommendations specifically include practical management of pain and fatigue.
  • A pain management programme where available. These are multidisciplinary programmes designed to reduce the impact of pain and help people return to meaningful activity, not to tell them the pain is imaginary. The Royal Free London’s NHS explanation describes physiotherapy and psychology working together to help people live better with persistent pain.
  • Psychological skills such as acceptance and commitment therapy or cognitive behavioural approaches when appropriate. These can help with fear, attention, sleep, grief and activity confidence; they are not proof that pain is “all in your head”.
  • A medication review. NICE recommendations differ between chronic primary pain and pain caused by another condition. Do not stop prescribed medication suddenly. Ask what each medicine is targeting, whether it is helping, what the harms are and how any change would be made safely.

Progress is not only a lower pain score. It might be sleeping more reliably, walking to the kitchen with less fear, returning to part of a hobby, needing fewer recovery days or feeling more confident about when to seek help.

Questions worth asking

  • What causes have been considered, and what would make you investigate further?
  • Do you think this is primary, secondary or mixed persistent pain?
  • Could my movement pattern, mobility aid or guarding be adding strain?
  • Can I be referred to an FND-aware physiotherapist, occupational therapist or pain service?
  • What is a safe plan for flares, and when should I contact NHS 111 or seek emergency help?
  • What is each medication meant to do, and how will we judge whether it is worth continuing?

Frequently asked questions

Can FND pain be severe?

Yes. Pain alongside FND can be severe and disabling. Severity alone does not reveal the cause, so new, sudden or changing pain still needs appropriate medical assessment.

Does persistent pain always mean ongoing damage?

No. Pain can come from injury, inflammation or another condition, but persistent pain can also continue after tissues have healed or without ongoing damage. A clinician should assess the pattern rather than assuming either explanation.

Can pain make FND symptoms worse?

Pain can increase overall nervous-system load and may coincide with more weakness, tremor, fatigue, brain fog or functional seizures for some people. Tracking can help identify your pattern, but a correlation does not prove pain is the only cause.

Should I stop pain medication because I have FND?

No. Do not stop prescribed medication suddenly or without medical advice. Treatment guidance depends on the type of pain, other conditions, benefits, harms and withdrawal risks. Ask for a structured medication review.

Sources and review basis

This article was reviewed against current sources on 12 July 2026. It is general information, not individual medical advice.