Have the following symptoms persisted or recurred during the past 6 months?	Present	Symptom severity in the past month: absent (0), mild (1), moderate (2), and severe (3)
1. Impaired function: there is loss of mental and/or physical stamina and a substantial reduction in ability to take part in personal, educational, and/or social activities	Yes [ ] No [ ]
2. Post-exertional symptoms: normal activity or mild/moderate exertion is followed by worsening of malaise, fatigue, and other symptoms. Recovery takes more than 24 h	Yes [ ] No [ ]
3. Fatigue: the fatigue is not the result of ongoing exertion, is not relieved by rest, and is medically unexplained. Fatigue can worsen with prolonged upright posture	Yes [ ] No [ ]
4. Sleep problems: sleep is unrefreshing with disturbed quantity or rhythm that can include daytime hypersomnia, nighttime insomnia, and day/night reversal	Yes [ ] No [ ]
5. Cognitive problems: any of the following: difficulty in concentration or focusing, difficulty understanding information and/or expressing thoughts, difficulty finding words or numbers, impaired short-term memory, absent mindedness, slowness of thought. Cognitive problems can be provoked by, or worsen with prolonged upright posture and/or physical or mental activity. Some young patients may not recognize these problems, but they might be noticed by a parent or teacher.	Yes [ ] No [ ]
6. Pain: can be widespread or localized, commonly seen are: chronic daily headaches, myalgias, abdominal pain, joint pains, sore throats, and painful lymph nodes. Pain can be worsened by prolonged upright posture. Rarely is pain absent	Yes [ ] No [ ]
Total symptom severity score: