You cough. You sniffle. You think you might feel a fever coming on. It’s a bad flu year—every year seems to be a bad flu year—and so you fear the worst. But is it really the flu?
The flu—influenza, if we’re being formal—is a virus that causes many of the same vague, sick-ish symptoms as colds and other infections. These include fever, cough, runny nose, headache, fatigue, and so on. There are many cold viruses, but they usually won’t give you a fever or body aches, and symptoms tend to come on more gradually. (Sick right now? Obsess over this CDC chart of the differences.)
Flu is also no relation to “stomach flu,” which is just a nickname for any illness that causes vomiting and diarrhea. You can get those symptoms with the real flu, but they’re like the side dishes where coughing, fever, and body aches are the main course.
One handy rule of thumb is that cough plus fever, in a community where the flu is already circulating, equals flu around 80 percent of the time, says Dr. Pat Salber, a San Francisco-based emergency room internist.
To tell if you really have the flu, a doctor can do a test: either a rapid test while you’re in the office (these can have high rates of false positives, though) or a lab confirmed test that requires you to wait a day or two for the results. Most of us won’t get a test: if flu is going around and our symptoms sound about right, we’ll be told we have the flu and should rest. The tests are useful for people who are more at risk, like elderly folks.
Call (or Video Call) the Doctor, Okay?
There’s no great treatment for the flu if you’re an otherwise healthy adult; you can rest and you’ll feel like death for a few days, maybe a week, and then you’ll be fine. But it’s not useless to seek care. If you have a severe case, you may need help to keep your symptoms from getting worse. And if you’re told you have the flu but you keep getting sicker, get to the emergency room right away—a girl recently died when her flu-like symptoms turned out to be a more dangerous infection.
Dr. Salber says that in California, where emergency rooms are currently swamped with flu patients, the hospitals are asking people to call first. If you don’t have the flu, you can save yourself a visit to a flu-filled hospital. And if you do, the diagnosis is often simple enough to be made over the phone. Video visits (typically around $40) are also a great way to get a doctor’s opinion on whether you really need to seek care in person, and many health insurance plans offer a free hotline to a nurse for these sorts of questions.
People who are elderly, pregnant, or have other reason to be more at risk should seek care right away. If your doctor can get you a dose of an antiviral like Tamiflu within the first 48 hours, your illness might end up being a little shorter or a little less severe. Tamiflu doesn’t actually work very well, so the benefit is small, but it may be able to keep a bad case of flu from becoming life-threatening.
Multiple versions of the influenza virus exist, and some are more popular than others each season. This year’s most common flu virus is an H3N2 type, which wasn’t part of the mix in recent years. That means children are especially at risk: their immune systems have never seen this type of virus, while adults have.
My kids’ preschool recently wrote to parents that, because of this, doctors in our area recommend that we should seek care for young children right away in case they need Tamiflu. Except they made a mistake in the email, and said the crucial medicine was Theraflu. Please be advised: Theraflu is an over-the-counter cough medicine, and it is not a substitute for getting medical care for a sick kid.