See also

• Abdominal pain - chronic
• Anxiety: identification and management
• Child abuse

Key points

• Functional somatic symptoms (FSS) are common, real physical symptoms arising from altered brain-body or nervous system functioning rather than structural disease. Symptoms are not imagined, exaggerated, deliberate or under conscious control
• FSS can co-exist with medical conditions and may be triggered or exacerbated by illness, injury, stress or developmental factors
• Diagnosis should be made positively, based on clinical features and examination findings, rather than by exclusion alone
• Clear explanation, reassurance and early functional rehabilitation are central to effective management
• Unnecessary investigations and fragmented care can inadvertently worsen symptoms and functional impairment

Background

• Functional somatic symptoms (FSS) are understood as conditions of altered nervous system functioning, in which the brain's processing of bodily signals, movement, sensation, or autonomic responses becomes dysregulated. This can result in symptoms such as pain, fatigue, dizziness, weakness, gastrointestinal disturbance, or episodes of altered responsiveness
• FSS describe physical symptoms that cause genuine distress and functional impairment but arise from a change in nervous system functioning rather than structural disease identifiable on standard investigations
• Some children with FSS have a concurrent medical illness, often with overlapping symptoms
• Importantly
  • symptoms are real and experienced as physical, not psychological complaints presented in physical form
  • FSS are not the result of malingering, factitious disorder, or conscious fabrication
  • psychological and social factors may contribute to symptom onset or persistence, but are not required for diagnosis
  • children and young people with FSS often have high health engagement, strong illness beliefs, and significant functional disruption, particularly to school attendance and daily activities
• There is a range of terms used for FSS including medically unexplained symptoms, Somatic Symptom and Related Disorders, and persisting physical symptoms. FSS has been chosen as the preferred term for this guideline, as it reflects current understanding and supports a collaborative, recovery-focused approach to care
• Children with neurodivergence may require early specialist input as communication differences, sensory sensitivities, and overlapping functional symptoms may influence presentation and management

Suggested approach to suspected FSS

• Assess and screen for red flags
• Identify positive features
• Minimal investigations
• Explain diagnosis
• Functional rehabilitation plan

Assessment

History

• Symptom characteristics, ie location, time course, triggers, fluctuation, what improves and worsens symptoms
• Current psychosocial assessment (children and their families) or HEADSSS screen (adolescents)
• Functional impact of symptoms, eg school attendance, work, social activities and relationships, physical activity, activities of daily living, mobility
• Current medications and response
• Past medical and psychiatric history including healthcare utilisation and a past history of FSS
• Family history of FSS, or other serious or chronic physical or mental health conditions
• Developmental history

Examination

• Thorough physical examination relevant to affected body system/s
• General screening examination to confirm diagnosis of FSS and to exclude any reversible and/or serious organic contributors to the symptoms
• Assess for complications of current disorders

Red flags

The following features warrant careful assessment and may require further investigation or referral

• persistent, consistent focal neurological deficits
• progressive symptoms without fluctuation
• objective weight loss, growth failure, or persistent fever
• nocturnal symptoms that wake child from sleep
• syncope associated with exertion or cardiac symptoms
• abnormal neurological examination that is reproducible and congruent
• new onset seizures with features concerning for epilepsy

The presence of red flags does not exclude FSS but may indicate co-existing pathology

Clinical features suggesting a diagnosis of FSS

• Symptoms that fluctuate over time, context, attention, or stress
• Inconsistency between symptoms and recognised disease patterns
• Variability in examination findings
• Symptoms that improve with distraction or automatic movement
• Marked functional impairment disproportionate to objective findings
• Co-existing fatigue, pain, sleep disturbance, or autonomic symptoms
• Hyperventilation on clinical assessment
• Recurrent healthcare presentations with limited diagnostic yield

These features should be framed as positive indicators of functional symptoms, not as evidence that symptoms are "not real"

Diagnosis of FSS should be

• Positive, based on identifiable clinical features
• Proportionate, ensuring safety while avoiding excessive testing
• Collaborative, with clear explanation provided to the child and family
• Diagnosis does not require exhaustive exclusion of all possible organic disease

Multidisciplinary assessment

Consider early referral for multidisciplinary assessment (including mental health assessment) if

• symptoms are causing enough distress and/or functional impairment to require admission
• significant or sustained functional impairment due to symptoms (eg non-attendance at school, loss of social connections)
• a lack of consensus within the treating team regarding a diagnosis of FSS
• social complexity and/or complex risk (eg exposure to family violence, bereavement, food or housing insecurity)
• concern that symptoms are being intentionally produced

Management

Investigations

• There are no investigations that will confirm a positive diagnosis of FSS
• Investigations are generally not required. They should be avoided once a functional diagnosis is established unless new symptoms/red flags emerge
• If performed, they should be
  • targeted and clinically justified
  • focused on excluding serious or reversible conditions
• Investigations can
  • reinforce illness beliefs
  • increase anxiety
  • delay recovery
  • lead to iatrogenic harm
• Investigation results should be clearly documented and shared with all clinicians involved. Identifying results that would prompt reassessment can be helpful

Treatment

• Supporting children and their carers to understand a diagnosis of FSS is an important component of management and is positively associated with recovery
• Clear confident explanation is a core therapeutic intervention. Key elements include
  • naming the diagnosis clearly as FSS
  • explaining that symptoms arise from how the nervous system is functioning, not damage
  • reassuring that symptoms are real and potentially reversible
  • outlining a clear plan focused on recovery and function
• If a functional cause is suspected early on, it can be helpful to include this as part of the working diagnosis in discussion with the child and family at that point. Delayed introduction while awaiting the exclusion of organic causes can be counterproductive
• Treatment is most effective when it occurs as part of an ongoing therapeutic relationship
• Many children presenting to primary and secondary care settings with FSS do not require a multidisciplinary assessment and will respond to a management approach that includes:
  • acknowledgement that the symptoms are real and that the impact on their experience and function is taken seriously. This may include asking about the symptoms and their impact at subsequent appointments
  • simple reassurance and sharing an explanation for the symptoms that makes sense to the child and their family, often including describing a link between mind and body (see table below for examples)
  • A focus on functional recovery. This usually requires children to return to usual activities despite ongoing symptoms. It can be helpful to acknowledge that this may be uncomfortable and to provide some reassurance that a return to function will not be harmful and will support recovery
• Psychologically informed approaches such as mindfulness, and cognitive and behavioural strategies, can be a helpful adjunct to reassurance and functional rehabilitation. A trusting therapeutic relationship and ongoing psychoeducation can support children and their families to accept psychological approaches as part of their care. Whilst many paediatricians are skilled in incorporating psychologically informed strategies for FSS, children with more complex presentations may also benefit from referral to a mental health specialist to supplement their ongoing medical care
• If there is concern after assessment that the symptoms are being intentionally produced by a carer, urgent referral should be made to a forensic service and consideration given to mandatory reporting responsibilities

Important components of management

Ideally avoid

• repeated re-investigation once diagnosis is established
• conflicting explanations from different clinicians
• telling families "nothing is wrong"
• attributing symptoms solely to anxiety or stress
• delaying diagnosis until all tests are complete

Consider consultation with local paediatric team when

• symptoms are recurrent or persistent
• history or examination indicate there may be undiagnosed pathology (see Red flags)

Consider consultation with specialist Child and Adolescent Mental Health service when

• symptoms are complex, or severe
• there are coexisting mental health problems that require acute management and that are beyond the comfort of the clinician
• significant risk is identified for the child or others

Consider discharge when

• appropriate alternative follow-up is arranged. This may include a plan for community follow-up (eg GP) or community support for functional rehabilitation (eg physiotherapist, psychologist)

Parent information

• FSS Information for children, young people and their families, QLD government
• FND Australia
• Neurosymptoms.org FND Guide Factsheets
• Bodysymptoms.org

Additional resources

• Treatment of Functional Seizures in Children and Adolescents: A Mind-Body Manual for Health Professionals

Last updated June 2026