Pain, Fatigue and Fluctuating Capacity

Pain, Fatigue and Fluctuating Capacity

What if your capacity changes from day to day, and therapy assumes it doesn’t?

What CBT offers people living with pain and illness

CBT for pain does not aim to prove the pain is in the mind. It looks at what the pain or illness has come to mean, how the person copes, what they fear, how they choose activities, and how self-criticism makes adaptation harder. Done well, it can reduce distress and help people take part in more of what matters to them.

The evidence is real but modest. A 2020 Cochrane review found that, compared with usual care, CBT had small benefits for pain, disability and distress in chronic pain. Compared with other active treatments, the benefits were very small. Williams et al., 2020 NICE’s guideline on chronic primary pain says CBT or ACT may be considered, notes the evidence for CBT was not high quality, and found no basis for preferring one over the other. NICE NG193

ME/CFS: where the guidance is specific

For ME/CFS, NICE’s 2021 guideline is unusually clear. It says CBT may help some people manage symptoms but is not curative. It says CBT should be offered only if the person wants it, and should not assume that “abnormal” illness beliefs and behaviours cause the condition. It advises against programmes based on fixed incremental increases in physical activity or exercise, such as graded exercise therapy. NICE NG206

The guideline describes post-exertional malaise: a worsening of symptoms that can follow even minimal physical, cognitive, emotional or social activity, often delayed. It supports energy management within a person’s own limits instead of fixed increases.

This guidance is specific to ME/CFS. It is not a rule for every condition. For chronic primary pain, NICE recommends exercise programmes, and for some people gradually building activity is genuinely helpful. The point is not that activity is always harmful. It is that the right approach depends on what the body is actually doing, and that has to be established, not assumed.

Six things that can look the same

“Doing less” can mean very different things. A good formulation separates them:

These need different responses. Only the first is a candidate for exposure-style work. The fifth is often where CBT helps most.

The boom-and-bust cycle

Many people with fluctuating conditions know this pattern well. A better day arrives. There is a backlog of things undone, and guilt about it. They do as much as they can. A crash follows. During the crash, guilt and frustration build. On the next better day, they overdo it again.

CBT can help here, not by pushing activity up, but by working on what drives the cycle: rules such as “I must make up for lost time” or “resting on a good day is wasting it”, and the self-criticism that follows a crash. Some people use the lived-experience language of “spoons”, from Christine Miserandino’s spoon theory, to describe a limited daily supply of energy. Whatever language is used, the aim is a more predictable life, not a more productive one.

Pacing itself is more than a budget. It can mean planning activity and rest across the day and week, breaking tasks into smaller parts, alternating different kinds of effort, stopping before symptoms rise, and adjusting the plan as capacity changes.

The cycle is not only driven by the person. Unavoidable demands, insufficient care, inaccessible systems and appointments that cannot be moved all push people into boom and bust. A formulation should include them.

Pacing is useful, but it is not a moral virtue. Sometimes a person will knowingly spend energy on something that matters. A chosen activity can still bring a flare or a setback. Choosing it removes the blame, not the physical consequences.

Look at delayed consequences

Standard CBT reviews often ask how an activity went. For fluctuating conditions, the more important question may be how the next day, or the day after that, went. Post-exertional symptoms and pain flares are often delayed. An activity diary that only records the day itself can make an unsustainable plan look like a success.

A moment in the session

An illustrative exchange, written for teaching. It is not a real session.

When the therapy itself needs to flex

Fluctuating capacity affects how therapy is delivered, not just what it discusses. It helps to agree in advance:

• what happens to sessions during a flare: shorter, online, by phone, or postponed without penalty;
• what between-session work looks like on a bad day, including “nothing”;
• how missed sessions and unfinished tasks will be discussed, without blame;
• how progress will be judged, so that a flare is not read as therapy failing.

Shame, grief and “I’m lazy”

Self-criticism is one of the places CBT can help most. “I’m lazy”, “I’m letting everyone down” and “a real adult would cope” are often harsh conclusions drawn from accurate facts about reduced capacity. They are worth examining.

Grief deserves room too. Losing a job, a sport, a role or a version of the future is a real loss. CBT does not need to reframe grief away. Sometimes the most useful thing is to recognise that the sadness fits the situation.

Signs of change

• Fewer crashes, or crashes that are less severe.
• Less guilt about resting.
• Choosing what to spend energy on, rather than trying to do everything.
• Being able to tell a fear-driven limit from a physical one.
• Taking part in something valued, in a way that is sustainable.
• Asking for support earlier.

None of these require lower symptom scores. Success might mean less shame, more usable support or better participation, with the condition unchanged.

Where to slow down

• Symptoms are new, worsening, or not yet medically understood. These need medical assessment, not a psychological explanation.
• An activity plan meets ME/CFS or another condition with post-exertional symptoms.
• The person is being pressured, by services, family or themselves, to do more than their body allows.
• The “goal” is set by what others want rather than what the person values.

For therapists

• Am I measuring success by output or by sustainability?
• Have I asked about the days after an activity, not just the day itself?
• Does my formulation treat rest as avoidance?
• Do I know the specific guidance for this person’s condition?
• Have I agreed in advance what happens to therapy during a flare?

A different experience

Some people with stable chronic pain find gradually building activity genuinely freeing, and want a therapist who will encourage them. That is consistent with the guidance for chronic primary pain. The disability-informed point is not “never increase activity”. It is that the plan should follow the body, and the person, not a fixed schedule.

Evidence and status

• Sources checked in October 2026, using targeted searches rather than a systematic review. “We have not located” means our searches did not find it, not that it does not exist.
• Documented guidance: NICE NG206 for ME/CFS and NG193 for chronic primary pain.
• Research: the 2020 Cochrane review of psychological therapies for chronic pain, showing small benefits for CBT compared with usual care.
• Lived-experience frameworks: spoon theory and pacing, widely used by disabled and chronically ill people.
• Our synthesis: the six-way distinction above and the focus on delayed consequences. We have not located trials testing CBT protocols built specifically around fluctuating capacity across conditions.

A question worth carrying: what did this cost, and when was the cost paid?