The FUNCAP Questionnaire Explained: Measuring Severity in ME/CFS and Long COVID

Anyone looking into pacing for ME/CFS or Long COVID will sooner or later come across the term FUNCAP. Over the past few years, the questionnaire has established itself as one of the best-documented tools for capturing disease severity more objectively – as a complement to the plain gut feeling of "today is worse than usual." This article explains what's behind FUNCAP, how the scoring works, and where its limits are.

What is FUNCAP?

FUNCAP stands for Functional Capacity and is a questionnaire for structured self-assessment of functional capacity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). It was developed in a patient-informed study and published in a peer-reviewed journal (Journal of Clinical Medicine, MDPI). Its goal is to capture both current severity as precisely as possible and to make disease progression trackable over time – something especially valuable for a strongly fluctuating condition like ME/CFS.

How is the questionnaire structured?

FUNCAP exists in two versions:

• The long version (55 questions) for a thorough initial assessment, for example in a diagnostic context or for insurance and disability applications.
• The short version (27 questions) for regular monitoring in everyday life, without overloading patients at every check-in.

Both versions use the same seven-point response scale from 0 to 6 – from "not possible at all" to "no functional limitation." Rather than a single extreme day, respondents rate a typical day within the past month, to realistically account for both "good" and "bad" days.

What is FUNCAP used for?

The questionnaire is used in several contexts:

• Clinical severity assessment – as a structured complement to the medical conversation.
• Progress tracking – repeated regularly, FUNCAP makes deterioration or improvement visible over months, which can be especially useful in a pacing context.
• Evidence for disability benefits – the extended version is used in some countries to help document work capacity.
• Assessment in Long COVID – the questionnaire is increasingly discussed beyond its original ME/CFS target group, for example in post-COVID courses with similar symptoms.

What FUNCAP can't do

Like any self-assessment questionnaire, FUNCAP captures a subjective snapshot, not an objective lab result. It doesn't replace medical diagnostics and should always be considered alongside a clinician's assessment. It also measures severity itself – it doesn't provide an automatic pacing recommendation or predict how much exertion is "safe" on a given day. For that, you additionally need your own observation of PEM patterns in daily life, for example through a crash diary.

FUNCAP and pacing: how do they fit together?

FUNCAP and pacing complement each other well but measure different things: FUNCAP documents severity over weeks and months, while pacing tools like mypacing tend to support short-term exertion management in daily life – through a crash diary, wearable analysis, and pattern recognition. Combining both approaches gives you visibility into both the long-term course and day-to-day exertion management.

Note: mypacing is not a medical device and does not replace medical diagnosis or treatment. FUNCAP is a self-assessment tool and does not replace a medical examination.