Winner of the American Association for the Advancement of Science/Subaru Science Books & Films Prize for Outstanding Science Series

How are you feeling

Most of the time you feel fine, but sometimes you get sick. Sometimes a germ catches up with you.

Germs are all around you, but they are too small for you to see. Many germs are harmless, but two kinds, viruses and bacteria, can make you sick. Read and find out about germs, how they can make you sick, and how your body works to fight them off and keep you healthy.