Standard questionnaires include the UKMEB Symptoms Assessment Questionnaire (SAQ) [
53], to aid diagnosis and the Participant Phenotyping Questionnaire (PPQ), for severity profiling [
54] or the DePaul Symptom Questionnaire, allowing diagnosis and symptom severity profiling [
6]. The Impact on function and quality of life may be measured by standard instruments, such as Rand-36 [
55,
56], some of which have been validated in many languages. The Epworth Sleepiness Scale [
57] can be used to assess excess daytime sleepiness and as a screening for obstructive sleep apnoea. Other instruments may be used to screen for mood disorders, e.g., neuroQOL [
58] or HADS [
59] for depression and anxiety or GAD-7 [
60] for anxiety. Fatigue severity may be measured by instruments validated for ME/CFS, e.g., the fatigue severity scale [
61]; visual scales such as pain and fatigue analogue scales are simple to use [
62,
63]. The same applies to sleep disorders (e.g., the Pittsburgh Sleep Quality Index [
64]), and autonomic symptoms (e.g., Compass 31 [
65]. A diagnosis of fibromyalgia may be established with a good degree of confidence by the annotation of pain symptomatology in pictorial representation of the human body [
66]. The same is true for the evaluation of hypermobility syndromes, using the Beighton criteria [
35].