You’re contagious one day before symptoms start and up to five days after they begin. So yes, you probably gave it to your coworker before you even felt sick. Sorry. That’s the flu’s dirty trick—you’re spreading germs while you’re still shopping for tissues.
Once your fever is gone for 24 hours (without meds), you’re generally safe to leave the house. But here’s the catch: that cough? If it’s still wet and productive, you can still spread the virus. So wear a mask or just stay home and binge-watch bad reality TV for one more day. Your friends will thank you.
Fevers are the main clue. If your temperature is 100.4°F (38°C) or higher, stay put. Even if you feel okay at noon, fevers love to return by evening. Don’t let the sneaky fever trick you into a relapse.
When to worry (and when to just suffer)
Most flu cases are miserable but harmless. But if you have trouble breathing, chest pain, or a fever that lasts longer than three days, see a doctor. That’s not just the flu being a jerk—that could be pneumonia. Don’t mess with that.
How long are you contagious when you’re sick? | Body ache, Sick, Flu fever
Also, if you start feeling better and then suddenly get worse, call your doctor. That’s a red flag for a secondary infection. Your immune system is exhausted, and bacteria love a tired host. Not cool, bacteria.
For everyone else: hydrate, sleep, and accept the snot. Drink more water than you think you need. The fever cooks you from the inside, and you’re basically a dried-out sponge. Soup, tea, electrolyte drinks—your body needs fluids like the Sahara needs rain.
