Unrefreshing sleep
Difficulty concentrating
Problems with short-term memory
“Brain fog” or slowed information processing
Orthostatic intolerance — feeling worse when standing or sitting upright
Light-headedness or dizziness when upright
Muscle pain
Joint pain without obvious swelling
Headaches
Sore throat
Tender or swollen lymph nodes
Flu-like feeling
Chills
Night sweats
Nausea
Gastrointestinal problems
Abdominal discomfort