What Uses Your Available Capacity?

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For the Person With FND
For Family, Friends, and Other Supporters
For Clinicians and the Care Team
Research and Sources

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For the Person With FND

You haven’t moved much. So why are you exhausted?

Imagine spending an hour filling out forms for an appointment. You haven’t lifted a box or climbed a flight of stairs. Yet when you’re done, you feel worn out.

That can be confusing—especially if someone asks what you did all morning.

Physical activity is only one kind of demand. Thinking, listening, reading, dealing with noise, managing pain, making decisions and being around people can require effort too.

Earlier in the course, we introduced available capacity as a way to picture how much you can manage before you need to change tasks or recover. It’s a useful planning idea, not a laboratory measure or an exact number of energy units. [1][2]

One day isn’t every day

The same activity may feel manageable on Tuesday and overwhelming on Wednesday.

Maybe Tuesday came after better sleep. Maybe Wednesday began with a migraine or an unexpectedly busy phone call. You may not know why the difference happened.

Variable ability does not make yesterday’s success false or today’s difficulty less real.

Capacity also depends on how you do something. Ordering groceries on a quiet phone may cost less effort than navigating a crowded store. Using a chair to prepare food might leave room for a conversation afterward. An adaptation can protect participation rather than merely reduce activity.

Activities have different costs—and different values

A shower, a medical appointment and an enjoyable visit may all take effort. But they aren’t interchangeable in what they mean to you.

A plan that only protects chores but leaves no room for pleasure isn’t necessarily a good plan. Nor should every enjoyable activity come with guilt.

Sometimes a support or accessible tool makes the same activity less demanding. Sometimes another health condition—such as a sleep disorder, migraine or orthostatic problem—requires treatment in its own right.

You don’t need to measure everything

Constant counting can become a job of its own. If a pattern doesn’t help you make a decision, you don’t have to keep tracking it.

Something to think about: What costs you energy that other people may not notice? What activities are worth protecting because they give something back to your life?

One small step: Pick one ordinary demand that could be made easier. You might break a form into sections, lower background noise or use a sitting position for a task. The goal is not to prove that your capacity increased. The goal is to make a day more livable.

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For the Person With FND
For Family, Friends, and Other Supporters
For Clinicians and the Care Team
Research and Sources

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For Family, Friends, and Other Supporters

Not everything tiring looks like exercise

Imagine accompanying someone to an appointment. They sit for most of the visit. Later they can barely manage a conversation.

It may be hard to understand why, especially if the only activity you noticed was sitting. But the person may have been managing pain, concentrating on explanations, coping with lights or sounds, finding words and remembering instructions.

Our course uses available capacity as a way to describe what a person can manage in a particular situation—not a fixed quantity of energy that can be measured or spent like money. [1][2]

A spouse and carer explained how several health problems affected their household:

Ask about the task, not just the clock

Rather than saying, “But you only did that for fifteen minutes,” ask which part was difficult. Was it standing, moving, bright light, noise, the mental work of following a discussion or the journey afterward?

The person may know the answer—or they may not. You can help simplify a task, divide chores, carry items, use written instructions or protect time for something they enjoy, depending on what they want.

A supporter has capacity too. Agree what help is realistic; if needs exceed what you can provide, that’s a care-planning issue rather than a personal failure.

When to involve professionals

OT can analyze everyday task demands and accessibility. PT can assess movement and safety in relation to activity. Primary care or relevant specialists should evaluate fatigue, sleep disorders, migraine, pain, orthostatic symptoms or other coexisting conditions; new or substantially changed symptoms need reassessment. Psychologists may help with adjustment or mental-health needs if desired, but cannot substitute for investigating medical contributors.

“she’s in bed probably half the week through either chronic fatigue or fibromyalgia pain.”

Figure 1. Community experience. A spouse reports coexisting fatigue and pain. These are not automatically attributed to FND. Original public source. [4]

Something to discuss together: “Which part of today used the most effort, and what would you like to save energy for?”

One small thing: Choose one adaptation the person welcomes—perhaps written directions, a quieter setting or help with one household task. The point is improved participation, not proving how much capacity they have.

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For the Person With FND
For Family, Friends, and Other Supporters
For Clinicians and the Care Team
Research and Sources

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For Clinicians and the Care Team

“Tired” is a description, not a diagnosis

Available capacity is useful planning language, not a measured pool of neuronal energy. Begin by asking whether the person means sleepiness, muscle fatigability, cognitive strain, pain-limited performance, sensory overload, orthostatic symptoms, post-event recovery, delayed symptom exacerbation or several phenomena together. The same visible task can impose very different demands depending on setting, medical comorbidity, cognitive load and accessibility. [1][2]

OT can use activity analysis to identify standing demands, executive load, sensory input, communication barriers and transport or caregiver reliance. Physiotherapy can identify safe movement and endurance goals while accounting for fall risk, coexisting motor disability and whether exertion is tolerated. Psychology/neuropsychology can address adjustment, attentional load and wellbeing without treating all fatigue as anxiety or avoidance. Sleep, pain, migraine, autonomic and primary-care specialists should evaluate other relevant conditions in their own right.

Consider symptom and condition interactions without collapsing diagnoses

A person may have functional gait disorder, migraine, insomnia and POTS. An appointment may cost mobility effort, sensory tolerance, concentration and upright time. Improvement in one domain can make the appointment more manageable without proving it was the mechanism of every other domain.

Similarly, functional seizures may have prolonged recovery or surrounding flares that differ from the visible episode; a person with FCD may spend substantial effort processing instructions despite an acceptable performance on a short test. Functional visual symptoms or PPPD may make lighting and visually busy travel settings particularly burdensome. Functional speech symptoms can add a high communication cost when a visit uses repeated questioning.

Use the co-occurring conditions collection to review fatigue, migraine, persistent pain, fibromyalgia, sleep, tinnitus, IBS and autonomic complaints without claiming they are all FND symptoms. New or changing symptoms require separate clinical assessment.

A practical plan for the care team

Ask the person to identify one activity and one constraint. Arrange the most important communication at a time and in a format they can use. Define whether the goal is reduced fatigue, increased reliability, access to an essential task or preserving capacity for something pleasurable. Avoid mandatory minute-by-minute diaries or unsupported “battery” scores.

Evidence boundary: FND occupational-therapy recommendations concern individualized function and rehabilitation planning 1. ME/CFS energy-management guidance 2 is condition-specific and cannot be presented as a validated FND theory of fatigue.

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For the Person With FND
For Family, Friends, and Other Supporters
For Clinicians and the Care Team
Research and Sources

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Research and Sources

General neuroscience, FND research findings, proposed mechanisms, professional consensus and treatment trials are distinguished in this lesson. Practical scenes and suggested conversations are illustrative; they are not tested treatment protocols. Community excerpts are individual accounts and do not establish diagnoses, typical outcomes or treatment effects.

Citation	Figure	Full citation
[1]	—	Nicholson C, Edwards MJ, Carson AJ, et al. Occupational therapy consensus recommendations for functional neurological disorder. JNNP. 2020;91:1037–1045. doi:10.1136/jnnp-2019-322281. Original · PubMed. FND-CIT-0011.
[2]	—	NICE. Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management. NG206, 2021. Official recommendations · Official guideline mirrored by NCBI. FND-CIT-0206.
[3]	—	Bennett K, Diamond C, Hoeritzauer I, et al. A practical review of functional neurological disorder (FND) for the general physician. Clin Med. 2021;21:28–36. doi:10.7861/clinmed.2020-0987. Original · PubMed. FND-CIT-0001.
[4]	Figure 1	Public Reddit contribution, r/FND. Original. Wording and relevant context checked October 26, 2026. Individual experience. FND-CIT-0321.

Publication-readiness audit: October 26, 2026. Human authoring and the two subsequent lesson audits remain pending. Independent clinical review has not been claimed.