The CDC's rule: back to work when, for at least 24 hours, you are fever-free without medication and your symptoms are improving overall - typically five to seven days into the flu.
A rebounding fever resets the clock and deserves a medical call, since improve-then-crash can signal a secondary infection. After returning, take 5 more days of added precautions - mask, distance, ventilation - since shedding continues into the following week, and pace the energy side with a graduated return.
What to do
Common questions
When can I go back to work after the flu?
The CDC's current respiratory-illness rule gives you a clear test rather than a day-count: you can return to normal activities, including work, when for at least 24 hours both things are true - your symptoms are improving overall, and you have had no fever without taking fever-reducing medication. For a typical flu case that lands around five to seven days in. Two refinements keep the answer honest. First, the 24-hour clock resets if you spike another fever - a flu that rebounds is still flu, and the improve-then-crash pattern specifically deserves a medical call since it can signal a secondary infection. Second, after you return, the CDC advises five more days of added precautions - mask in close quarters, better ventilation, distance - because you can still shed virus into the following week, especially relevant if you work with older adults, patients, or the immunocompromised, who deserve the longer caution. The energy part of the answer: the flu's exhaustion famously outlasts its contagiousness, so a graduated return beats a heroic first day back. Pymander, a free AI doctor available 24/7 by text, can help you read your own timeline.