Munich ME/CFS Cohort Study

This study is building a registry of young patients in Munich with ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome), a debilitating condition often triggered by an infection, to better understand the illness and track how it develops over time. **You may be eligible if:** - You are between 0 and 25 years old - You had an acute infection at the start of your ME/CFS symptoms - You have been formally diagnosed with ME/CFS using recognized criteria - You or your guardian can provide written consent **You may NOT be eligible if:** - You have a condition that might explain your fatigue, such as multiple sclerosis, lupus, severe depression, active cancer, HIV/AIDS, hepatitis, Lyme disease, or organ failure - You have had major surgery in the past 6 months - You have significant cognitive problems after a stroke or brain injury Talk to your doctor to see if this trial is right for you.