Cold and flu: different viruses with similar symptoms

Dear Doctor: When my husband and I both got sick last month, he was diagnosed with a cold and I was diagnosed with the flu. What’s the difference?

Dear Reader: Both a cold and the flu are respiratory illnesses caused by a virus. The difference between the two is the type of virus that is involved.

The flu is caused by the influenza virus, of which there are four types – A, B, C and D. The seasonal …