context: You've been home sick a couple days, and there's only so much daytime television you can take. You're ready to go back to work. But common colds and the flu are very contagious. There are millions of cases of these upper respiratory infections every year. And colds are the biggest reason kids miss school and adults miss work. If you've been sick with a cold or flu, how long are you supposed to stay home, and when should you go back to your everyday routine? Experts generally agree that it's best to stay home as long as you have severe symptoms, like a cough with mucus, vomiting, diarrhea, fever, or fatigue, because you may be contagious. And the CDC recommends staying home at least 24 hours after your fever goes away unless you need to leave the house for medical care or other urgent reasons. Also, rest is an important part of getting over any illness, so there's another reason to take it easy while you feel sick. How quickly you recover from a cold or the flu depends on how healthy you are. In general, healthy people usually get over a cold in 7 to 10 days. Flu symptoms, including fever, should go away after about 5 days, but you may still have a cough and feel weak a few days longer. All your symptoms should be gone within 1 to 2 weeks. When you go back to work or school, make sure to cover your mouth when you cough and wash your hands often so you don't spread the illness to other people. These viruses can develop into serious illnesses like pneumonia in people who have weak immune systems, asthma, or other respiratory conditions. So if you have a chronic illness, your healing time may be different. If your child is sick, it's best for her to stay home until she feels well again. If she has a fever, nausea, vomiting, diarrhea, or any kind of pain, isn't hungry, or seems extra tired or clingy, she should stay home. But check with your child's daycare or school before you send her back to her regular schedules. Many places have rules about how long kids need to stay home. Usually it's at least a full day after they don't have any fever without medication. Colds are most contagious in the first 2 to 4 days after symptoms start. But they can spread up to a few weeks after that. Your symptoms will usually show up 2 to 3 days after you've been infected, so you may not know you're sick when you first get the virus. You can give other people your cold just by being around them. Your sneezes and coughs can send virus particles as far as 12 feet through the air where they can land in someone's mouth or nose or be inhaled into the lungs. Others can also catch your cold if they touch you or something you've come into contact with and then touch their mouth or nose. Like the common cold, the flu is caused by a virus, and it's likely to spread through coughs, sneezes, or even talking. Those actions can send droplets up to 6 feet away. It's also possible to get the flu by touching something with the virus on it and then touching your mouth or nose, but that's less likely. You can be contagious before you even know you're sick. The virus usually enters your body 1 to 4 days before you have any symptoms, and you can give it to someone a day before you feel anything up to 5 to 7 days after. And kids are contagious even longer. They can spread the virus for another week. Some people never show symptoms but can still give it to others.