Virus or bacteria?

Most infections are caused by a virus or bacteria.

Viruses cause the flu and the common cold. Antibiotic medicine cannot cure viral infections. But a doctor may prescribe antiviral medicine for severe cases of the flu or to prevent flu-related medical problems.
Bacteria cause ear infection and strep throat, among other infections. They can be treated with antibiotics prescribed by a doctor.

These general guidelines can help determine if you have a viral or bacterial infection:

Symptom	Virus	Bacteria
runny nose	often	rare
muscle aches	usual	rare
headache	often	rare
dizziness	often	rare
fever	often	often
cough	often	sometimes
dry cough	often	rare
coughing up mucus (also called phlegm or sputum)	often	often
hoarseness	often	rare
Do antibiotics help?	no	yes

When should I go to the doctor?

Go to the doctor if…

your flu symptoms seem severe or do not get better in 3 to 4 days
your cold symptoms do not get better in 7 days or if they get worse
you have a bacterial infection that can be treated with antibiotics
you are pregnant and have flu symptoms
you have a medical condition that the flu could make worse, such as asthma, emphysema or another kind of COPD (chronic obstructive pulmonary disease).

If you have questions, call the nurse line listed on your health insurance card or contact your health care provider.

Main ways to keep yourself and others from getting sick include:

Cover your mouth and nose with a tissue when coughing or sneezing. If you don't have a tissue available, cough into your sleeve or upper arm instead of your hand.
Wash your hands after coughing or sneezing, blowing your nose, and using the bathroom. You should also wash your hands before eating.