Diagnosis
To diagnose the flu, also called influenza, your healthcare professional does a physical exam, looks for symptoms of flu and possibly orders a test that detects flu viruses.
The viruses that cause flu spread at high levels during certain times of the year in the Northern and Southern hemispheres. These are called flu seasons. During times when flu is widespread, you may not need a flu test.
But a test for flu may be suggested to help guide your care or to know if you could spread the virus to others. A flu test may be done by a pharmacy, your healthcare professional's office or in the hospital.
Types of flu tests you may have include:
- Molecular tests. These tests look for genetic material from the flu virus. Polymerase chain reaction tests, shortened to PCR tests, are molecular tests. You also may hear this type of test called an NAAT test, short for nucleic acid amplification test.
- Antigen tests. These tests look for viral proteins called antigens. Rapid influenza diagnostic tests are one example of antigen tests.
It's possible to have a test to diagnose both flu and other respiratory illness, such as COVID-19, which stands for coronavirus disease 2019. You may have both COVID-19 and influenza at the same time.
Treatment
If you have a severe infection or are at high risk of complications from a flu infection, your healthcare professional may prescribe an antiviral medicine to treat the flu. These medicines can include oseltamivir (Tamiflu), baloxavir (Xofluza) and zanamivir (Relenza).
You take oseltamivir and baloxavir by mouth. You inhale zanamivir using a device similar to an asthma inhaler. Zanamivir shouldn't be used by anyone with certain chronic respiratory problems, such as asthma and lung disease.
People who are in the hospital may be prescribed peramivir (Rapivab), which is given in a vein.
These medicines may shorten your illness by a day or so and help prevent serious complications.
Antiviral medicine may cause side effects. The side effects often are listed on the prescription information. In general, antiviral medicine side effects may include breathing symptoms, nausea, vomiting or loose stools called diarrhea.
Lifestyle and home remedies
If you have the flu, these measures may help ease your symptoms:
- Drink plenty of liquids. Choose water, juice and warm soups to help keep fluids in your body.
- Rest. Get more sleep to help your immune system fight infection. You may need to change your activity level, depending on your symptoms.
- Consider pain relievers. Use acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others) for fever, headache or achiness associated with influenza. Children and teens recovering from flu-like symptoms should never take aspirin because of the risk of Reye's syndrome, a rare but potentially fatal condition.
To help control the spread of influenza in your community, stay home and keep sick children home until the fever is gone, without the use of medicine, for 24 hours. Unless you're going to a medical appointment, avoid being around other people until you're feeling better. If you need to leave your home to get medical care, wear a face mask. Wash your hands often.