Did I make you sick?

You wake up with a sore throat and you feel a cold coming on. Do you stay home and rest, or do you head out the door to work? If you pick the latter, you know you risk spreading your germs to others. But the reality is the damage may have already been done.

Whether you have a cold, the flu or bronchitis, you start sharing your germs before you begin to feel sick. The typical rule of thumb with respiratory illnesses is that you’re contagious a day or two before the onset of symptoms and it can last five to seven days after you get symptoms.

If you have strep throat, you’re contagious a day or two before you feel sick and for two to three weeks after unless you take an antibiotic, then you are no longer considered contagious after 24 hours. When it comes to stomach viruses and pink eye, you’re usually contagious until the diarrhea runs its course or eye discharge clears up.

The way the germs spread depends on the illness. 

• Respiratory illnesses: For colds, flu, strep throat and bronchitis, coughs and sneezes are the main culprits. They both send droplets into the air that can settle on surfaces. If someone touches the same surface and then touches their eyes or mouth, they could get sick. Sinus infections aren’t usually contagious, since most people don’t get a cough with a sinus infection.
• Gastrointestinal illnesses: When you’ve got a stomach virus with diarrhea, it spreads through the bowel movements. Poor hand hygiene can spread the illness.
• Orbital illnesses: Pink eye causes discharge that’s hard not to wipe away. Touching the eye discharge and then another surface can share it with others.

If you’re sick or around someone who is sick, there are several ways to prevent the spread of germs.

• Wash your hands: At the end of the day, this is the most important thing you can do. Wash your hands with soap and water, taking the time to scrub them for at least 20 seconds. If you’re unable to wash your hands, use an alcohol-based hand sanitizer.
• Cough or sneeze into your elbow: If you have to cough or sneeze into your hands, cover your nose and mouth with a tissue first, then wash your hands.
• Stay home: Limit your exposure to other people and get some rest. Taking it easy allows your body to focus on fighting the illness.
• Don’t share things: Don’t eat off of anyone’s plate and don’t drink out of anyone’s glass. 
• Take your medication: If the illness is caused by bacteria, your doctor may prescribe an antibiotic, which you should take as directed. Most viruses are treated with supportive care, such as rest and fluids. The flu is often treated with an antiviral medication called Tamiflu, which can lessen symptoms and shorten the illness by a day.
• Take prophylactic medication: If you live with someone who has the flu, your doctor may recommend a once daily dose of Tamiflu, along with the influenza vaccination, to keep you from getting sick.
• Flush your sinuses: Periodically flushing the sinuses with saline using a neti pot or similar device can make a huge difference. It can remove excess mucus and keep the hairs and sinus cavity healthy.

Randell Wexler is an associate professor of family medicine at The Ohio State University Wexner Medical Center.