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The Flu? Pneumonia? How to Tell What You've Got

Blowing noseBy Heather Maloney
Beth Israel Deaconess Medical Center staff

Aches. Fever. Cough. Do I need antibiotics? Or should I just stay home and rest?

With all the germs swirling around this time of year, it can be hard to tell what you're suffering from, and if rest and fluids will do the trick or if you need to see a doctor.

Dr. Christine Harrington, a primary care physician at Beth Israel Deaconess Hospital-Needham, says that sorting it all out can be challenging.

"Viral and bacterial infections share many of the same signs and symptoms, so it can be hard to determine exactly which type of bug you have," she says. "But there are some general rules that can help you figure out when to see a doctor, and when it would be okay to stay at home and treat it with rest and over the counter medicines."

So, when you start feeling under the weather, Dr. Harrington offers these guidelines:

The Flu ...

  • Usually hits suddenly.
  • Is characterized by significant, head-to-toe body aches, fever and a dry cough. Other symptoms may include headache, sore throat and, occasionally, nausea and diarrhea.
  • The flu can be treated with anti-virals which work best if started within 48 hours of symptom onset. If you're over 65, pregnant, or have any chronic illness (such as heart disease, asthma, emphysema or active cancer), see your doctor immediately. They may choose to treat you with anti-virals.
  • If you are a generally healthy person, call your doctor to see if anti-virals are appropriate for you.
  • If you are short of breath, having trouble breathing, or seem to be getting worse with each passing day, call your doctor immediately.

Pneumonia ...

  • Always requires antibiotics.
  • Is characterized by fever, a significant cough which is generally productive of phlegm, shortness of breath and fatigue.
  • Adults with pneumonia often describe themselves as feeling wiped out and admit to missing more than one day of work "because I just didn't have the energy to go."
  • Pneumonia often comes on gradually (unlike the flu), and typically does not cause severe aches and pains like the flu.
  • If you're over 65, pregnant, or have any chronic illness and you suspect pneumonia, you should call your doctor immediately.

Bronchitis ...

  • Typically does NOT cause a fever.
  • Is characterized by a productive cough and irritated chest but usually does not make a patient short of breath or so fatigued that they are staying in bed and missing work.
  • In a healthy individual, rarely needs antibiotics.
  • If you smoke or you have asthma or any illness that affects your lungs, contact your doctor as you may need antibiotics.


  • Typically does NOT cause a fever.
  • Often does not need antibiotics.
  • Is characterized by thick, colorful mucus and a "heavy head."
  • Can be treated with over-the-counter therapies (such as decongestants and saltwater nasal spray) aggressively for seven days. If there is no improvement after seven days, call your doctor.

While it can be confusing, Dr. Harrington says there are a few rules of thumb.

"Often I ask my patients, 'Have you missed work because of this illness?' Most adults have to be significantly ill to miss work, so generally, I say, if you miss two days of work, you should see a doctor."

But, she points out, when in doubt, definitely call your doctor.

"Often times, your doctor may want to at least talk to you over the phone and hear firsthand how you're feeling in order to get an idea of what is really going on," Dr. Harrington says.

In the end, if you're unsure, your doctor will be able to guide you in deciding whether you can stay home or whether you need to be seen.

"The truth is, a picture is worth a thousand words," she says. "And if I think a patient may need an antibiotic or an anti-viral, I often will want to see them first."

Most of all, she says, it's important to listen to your body.

"If you feel unwell, achy and fatigued, rest," Dr. Harrington adds. "If you feel you are getting worse with each day or if you are not bouncing back the way you usually do, then by all means, speak to your doctor. "

Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.

Posted December 2011

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Beth Israel Deaconess HealthCare
(Off-site Primary Care Practices)