Your teen is cranky and tired. She sleeps all the time and complains of a sore throat, fever, achy muscles and belly pains. It could be the flu, but there's a good chance that she has mononucleosis, usually shortened to "mono." We've been through three bouts of it in our family, with one child getting a reinfection a few years later. Here are some tips to prevent mono infections and care for a teenager who has it. Read more at How to treat mono symptoms in teens