25/01/2026
Functional Neurological Disorder (FND) is a diagnosis that has become more prevalent in recent years due to increased research, understanding and the development of tests.
We support a number of participants with this condition and wanted to take a moment to raise awareness.
Functional Neurological Disorder (FND) is a condition in which people experience real, involuntary neurological symptoms that are not caused by structural damage or disease of the nervous system.
Instead, the problem lies in how the brain sends, receives, or processes signals. Brain scans and tests are often normal, but the nervous system is not functioning correctly.
FND is diagnosed using positive clinical signs, not by exclusion, and symptoms are not intentional or “psychological” in origin, even though psychological factors can contribute.
FND is best understood through a biopsychosocial model. No single cause applies to everyone.
Neurological factors:
- Disrupted brain networks involved in movement, sensation, and attention
- Heightened threat or error signalling in the brain
- Reduced automatic control of movement
Psychological factors:
- Trauma (cPTSD or PTSD)
- Chronic stress or emotional overload
- Maladaptive coping patterns (often unconscious)
Biological and physical triggers:
- Injury, surgery, infection, or illness
- Pain conditions
- Migraine or concussion
Symptoms vary widely between individuals and may fluctuate over time. Common presentations include:
Motor symptoms:
- Limb weakness or paralysis
- Abnormal movements (tremor, jerks, dystonia)
- Gait difficulties or collapse episodes
- Speech or swallowing difficulties
Seizure-like symptoms
- Functional (non-epileptic) seizures
- Altered awareness or responsiveness
- Shaking or convulsive episodes without epileptic EEG changes
Sensory symptoms
- Numbness or tingling/pins and needles
- Visual disturbances (blurred or double vision)
- Hearing changes
Cognitive and fatigue symptoms
- Brain fog
- Attention or memory difficulties
- Severe fatigue
Autonomic and bodily symptoms
- Dizziness or fainting
- Pain
- Functional bladder or bowel issues
Causes and Contributing Factors
There are various contributing factors and many people with FND do not have a clear psychological trigger. The absence of trauma does not rule out the diagnosis.
FND frequently co-occurs with other conditions, which can complicate diagnosis and management:
Mental health
- Anxiety disorders
- Depression
- Post-traumatic stress disorder (PTSD)
- Dissociative disorders
Neurological
- Migraine
- Epilepsy (FND and epilepsy can coexist)
- Functional dizziness/loss of balance
-Disequilibrium
Pain and fatigue
- Fibromyalgia
- Chronic fatigue syndrome / ME
- Chronic pain syndromes
Autonomic disorders
- Postural orthostatic tachycardia syndrome (POTS)
Neurodevelopmental
- ADHD
- Autism spectrum disorder (ASD)
- Alexithymia
FND symptoms are real, disabling, and involuntary. The nervous system is structurally intact but functionally disrupted. Diagnosis is based on positive neurological signs
Treatment is possible and often involves multidisciplinary care (neurology, psychology, physiotherapy, occupational therapy).
