Editor's note: Dr. Jennifer Shu, CNNHealth's Living Well expert doctor, is a practicing pediatrician and mother of two.
(CNN) -- The average adult gets a cold about two or three times a year, with each one lasting up to a week, or sometimes longer.
Staying home from work every time you are sick could add up to a lot of missed days. In fact, it has been reported that up to 40% of lost time from work is due to the common cold, totaling about 23 million missed days per year.
Even though it can be tempting to go to work while you're sick, here are some reasons why you are better off staying home:
You'll get other people sick
Germs can spread from direct contact with a sick person or his or her secretions (such as from handshakes or touching shared objects like doorknobs). Some viruses can live on the skin or other surfaces for at least a few hours and continue to infect others.
In addition, viruses can spray a few feet following a cough or sneeze. Especially in the earliest part of illness, when you are most contagious, stay home if you work in close quarters with other people or if you handle food.
It's also important not to go to work if you work with young children, the elderly or people with weak immune systems. The relatively minor illness you experience may cause more severe symptoms in these groups of people.
You'll be less productive
It is hard to know the exact financial and physical toll that an illness takes on an individual or employer. Sure, you'll be more productive than if you stayed home and didn't do any work at all, but you may not be as sharp or efficient when suffering from a cold.
It may take longer to recover
Pushing yourself and working too much in the early stages of illness may actually prolong your recovery time. Studies have shown that lack of sleep can weaken your immune system and make you more susceptible to colds.
Conversely, getting enough sleep can boost infection-fighting cells and antibodies so you can get well faster. Do yourself a favor and stay home and rest.
Ideally, we would all be able to rest and recuperate during a cold. If that's not possible, see if you can work from home so at least you won't spread your germs.
If you must go to work, try to keep your distance from others, wash or sanitize your hands often, and cover coughs and sneezes with a sleeve or elbow. You can also cover with a tissue but be sure to throw it away immediately and then wash your hands.
Disinfect touched objects such as phones, doorknobs, and computer keyboards, and consider avoiding sharing items such as pens.