If you're feeling under the weather, a viral upper respiratory infection may be to blame. That's what Dr. Dennis Perry at Meridian Primary Care in Okemos is busy treating this week.

The symptoms of the virus he's treating include: low-grade fever, sore throat, runny nose, and a mild cough that lasts for seven to 10 days.

If your fever lasts more than three days, you should see a doctor.

This type of cold is causing a lot of secondary infections. A secondary infection is when you get a viral infection, which knocks down your usual defense mechanisms, and allows a bacterial infection to take hold.

That doesn't start until a few days into it, and is more probable in someone very young, very old, or somehow debilitated.

The secondary infections Dr. Perry is seeing are pneumonia, sinusitis and ear infections.