How to test for flu
Two common kinds of tests are widely available to check for Influenza A and Influenza B strains of the seasonal flu. These include rapid influenza diagnostic tests (RIDTs) and molecular flu tests.
RIDTs are at-home tests that look for the presence of certain antigens (proteins) that are found in flu viruses. These rapid tests give you results in less than 30 minutes. Results tend to be more accurate if your signs and symptoms of flu are consistent with typical seasonal flu symptoms, as well as if your test sample is taken within 3 to 4 days of when felt sick. Also, RIDT results tend to be more accurate when there are high levels of the seasonal flu virus circulating in the community, such as during the fall or winter.
In contrast, molecular flu tests are designed to detect genetic material from seasonal flu viruses in a sample that you provide. They tend to have greater accuracy than RIDTs. Some molecular tests can give you rapid results in less than 30 minutes. Other molecular tests may take a few days before you get results, because the samples are sent to a lab; however, they have the greatest accuracy of all seasonal flu tests.
There are 2 types of molecular tests for the flu: Rapid molecular flu tests and molecular laboratory tests. Rapid molecular flu tests are performed in a healthcare setting. Molecular tests that require a lab to get results can be done in a healthcare clinic, but you can also get a test that allows you to collect a sample at home and send it to a lab for analysis.
There are also combination tests that can check for both flu and COVID, or for flu and RSV. Both types of combination tests are available as rapid molecular or molecular lab test formats described above. At-home tests are available for flu and COVID; at-home sample collection kits enable lab testing for flu and RSV.
For any flu test, a sample of fluid from your respiratory tract is needed. In a healthcare setting, you might have a sample taken by a provider who collects it by swabbing your nose or throat, or by performing a nasal wash with a saline solution that is then gently suctioned out. At home tests typically require you to use a swab in collecting a sample.
Testing for bird flu
Tests for
avian or bird flu are focused on identifying the specific Influenza A virus subtypes that are linked to respiratory illness in birds and other animals. If you’re concerned that you might have avian or bird flu, you should know that not everyone can get tested for it. Currently, avian flu testing is done in people who develop flu symptoms and work in settings with infected animals, such as dairy and poultry farms. However, as of January, the CDC recommends that people who are hospitalized and test positive for Influenza A should have their specimens subtyped to check for bird flu, too.
If you get flu symptoms and work in a place where you have exposure to animals that have been sick with bird flu, be sure to let your healthcare provider know. Your doctor can order you a test that can differentiate between the seasonal flu and bird flu.
Next steps
If you perform an at-home flu test and get a positive result, it’s likely that you have the seasonal Influenza A or B virus. Your doctor may prescribe antiviral treatment, but most likely, you will recover with self-care at home. This can involve getting rest, drinking fluids and taking over-the-counter medicines to help you manage fever, headache or muscle aches. Even if you receive a negative result, your healthcare provider can advise you on next steps
Regardless of whether or not you get a flu test, if you experience emergency flu-like symptoms—such as difficulty breathing, chest or muscle pain, dizziness, seizures, severe weakness, or worsening of any medical conditions you already have—make sure to get in touch with your doctor right away.
Read more about flu symptoms
