An in-depth report on the diagnosis, treatment, and prevention of colds and flu.
Common Cold and Influenza
Colds and influenza (flu) are respiratory tract infections caused by airborne viruses:
- The common cold is caused by more than 200 viruses. Rhinovirus is the most common cause.
- Influenza in humans is caused mainly by two viruses: influenza A and influenza B. There are many different strains and flu viruses constantly mutate.
Colds and the flu can share similar symptoms such as stuffed up or runny nose but there are also differences:
- Flu symptoms are usually more severe than the cold
- Fever is common with the flu but rare with colds
- Headache and extreme exhaustion are more common in flu than colds
- Sore throat is more common with colds than flu
The viruses that cause colds and flu are spread by direct contact with secretions or by being close to an infected person who coughs or sneezes. You can reduce your risk of catching these germs by:
- Frequently wash your hands and use hand sanitizer.
- Avoid touching your hands to your eyes, mouth, or nose.
- Clean and disinfect commonly touched surfaces and objects.
- Avoid crowded environments during cold and flu season.
- Get a flu vaccine.
The best way to avoid getting influenza is to get an annual flu vaccine. The U.S. Centers for Disease Control and Prevention (CDC) recommends that everyone over the age of 6 months receive a flu vaccine every year. There are two types of flu vaccines:
- Injectable flu vaccines (flu shots) use inactivated (killed) viruses. Flu shots may either protect against 3 strains of influenza (trivalent) or 4 strains (quadrivalent). Some high-dose flu shots are recommended specifically for people over age 65.
- Nasal spray flu vaccines use live attenuated (weakened) influenza viruses. They protect against 4 strains of flu viruses. In 2014, the CDC recommended the nasal spray vaccine for healthy children ages 2 to 8 years old.
Colds and flu are usually treated by resting and drinking lots of fluids. Most cases of flu and colds resolve by themselves within a few weeks. However, some people are at increased risk for developing serious influenza complications. They include young children, older adults, pregnant women, and people with chronic health conditions.
In 2015, the CDC recommended antiviral drug treatment for people at high risk for flu complications:
- Recommended antiviral drugs are oseltamivir (Tamiflu) and zanamivir (Relenza). Peramivir (Rapivab) is a new antiviral that is given intravenously to hospitalized patients.
- Antiviral drugs can reduce symptom severity and shorten the duration of illness by 1 to 2 days. They work best when started within 2 days of symptom onset. These drugs have a number of side effects.
- Antibiotics are not used to treat viral infections like the flu, but may be used if secondary bacterial infections develop.