The flu is an infection of the nose, throat, and lungs. It spreads easily. The flu is caused by an influenza virus.
Symptoms of Influenza
Once a person comes in contact with the virus, symptoms show up relatively quickly. People can start seeing symptoms 1-7 days after coming into contact with the virus. Most people will usually see symptoms within 2-3 days.
The first symptom most people will see is a fever. The fever can range from 102°F (39°C) to 106°F (41°C). Adults usually have a lower fever than children.
Other common symptoms:
- Body aches
- Flushed face
- Lack of energy
- Nausea and vomiting
After 2 to 4 days, the symptoms tend to disappear, but new symptoms arise:
- Dry cough
- Increased symptoms that affect breathing
- Runny nose (clear and watery)
- Sore throat
After 4 to 7 days the symptoms go away.
At the moment there is no medication that can cure influenza. Ultimately the best treatment for influenza is time and rest. However there are a couple things you can do to relieve some symptoms.
Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) help lower your fever. Most people feel better when the temperature drops by 1 degree.
Cough drops or throat sprays can help with your sore throat.
Most importantly, make sure you drink plenty of liquids and get plenty of rest.
Of course there are some cases of the flu that might be more severe. The following health issues may lead to more severe flu cases:
- Lung disease (including asthma)
- Heart conditions (except high blood pressure)
- Kidney, liver, nerve, and muscle conditions
- Blood disorders (including sickle cell disease)
- A weakened immune system due to diseases (such as AIDS), radiation therapy, or certain medicines, including chemotherapy and corticosteroids
- Other long-term medical problems
If you have one of these conditions, please contact your provider. They will most likely prescribe anti-viral medications.
The best things you can do to prevent influenza is to get a flu shot. It is recommended that you get one for every flu season. However some children between six months and eight years old may receive two vaccines per season.
If you have the flu:
- Stay in your home for at least 24 hours after your fever has gone.
- Wear a mask if you leave your room.
- Avoid sharing food, utensils, cups, or bottles.
- Use hand sanitizer often during the day and always after touching your face.
- Cover your mouth with a tissue when coughing and throw it away after use.
- Cough into your sleeve if a tissue is not available. Avoid touching your eyes, nose, and mouth.
Aoki FY. Antiviral drugs for influenza and other respiratory virus infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 45.
Centers for Disease Control and Prevention website. Inactivated influenza VIS. www.cdc.gov/vaccines/hcp/vis/vis-statements/flu.html. Updated August 15, 2019. Accessed October 19, 2020.
Centers for Disease Control and Prevention website. Live, intranasal influenza VIS. www.cdc.gov/vaccines/hcp/vis/vis-statements/flulive.html. Updated August 15, 2019. Accessed October 19, 2020.
Centers for Disease Control and Prevention website. What you should know about flu antiviral drugs. www.cdc.gov/flu/treatment/whatyoushould.htm. Updated August 31, 2021, 2021. Accessed March 11, 2022.
Havers FP, Campbell AJP. Influenza viruses. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 285.
Ison MG, Hayden FG. Influenza. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 340.
Treanor JJ. Influenza viruses, including avian influenza and swine influenza. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 165.