First, if you’re prone to allergies, or just an occasional flash of hay fever, rule it out: allergies rarely cause coughs, and the most they contribute to stomach troubles is maybe a mild stomach ache if you really have your nose going (and there will be a sore throat, too). Allergies will often cause itchiness—especially around your eyes. Fatigue can go both ways—if you’re an expert on your body, you might be able to tell what’s causing it.
Here’s the big one: allergies never cause fever. If you’re feeling ill, take your temperature.
Once you get the big, fat positive of a raised temperature, it’s time to rest, drink fluids, and support your immune system.
If it’s a cold, you’re contagious at least as long as you have symptoms (and remember, over-the-counter cold medicine is really just a symptom blocker—you aren’t better, and you’re still contagious, although it may make being sick more bearable).
Flu means you’re contagious for at least a week.
Ideally, everyone would stay home and take care of themselves when they were sick, getting all the care they need. But if you’re in a rush to return to work, go by school rules—give yourself 48 hours of being fever free before you consider yourself contagion free.
You can minimize spreading symptoms by coughing and sneezing into your elbow, running a humidifier, and keeping your workspace clean. Frequent hand washing is also a major barrier to the spread of disease.
If it is allergies, try a sinus rinse for symptoms relief.
What symptoms make you stay home?