If you find yourself with symptoms like a fever, runny nose, cough, sore throat, body aches, headache, and extreme fatigue during the colder months of this year, you may be one of the unlucky people who has caught this year’s strain of the flu.

The flu is a viral illness that is highly contagious and can be life-threatening, but because the symptoms of the flu can mirror those of other common illnesses, it can be hard to know whether you have the flu or a different virus.

If you’re wondering how they test for the flu, you may be surprised by the number of flu test options.

What Is Influenza and How Does It Spread?

Influenza, referred to colloquially as the flu, is a contagious illness that is caused by a group of viruses known as influenza. Unlike the common cold, which typically resolves with no complications, the flu is a serious illness that can cause life-threatening complications in some people. However, not everyone who gets the flu will have a severe case and everyone experiences the flu differently.

The flu is an airborne illness that spreads through tiny droplets of water that move through the air when an infected individual sneezes, coughs, or speaks. These tiny droplets contain the virus, which infect a new host when inhaled.

The flu virus can also live for short periods of time on surfaces, so it is possible to contract the flu by touching a surface that a person with the flu has touched and then touching your own eyes, nose, or mouth. While this method of transmission is less common, it is still possible, which is why practicing good basic hygiene like frequent handwashing is especially important during flu season.

What Are the Symptoms of the Flu?

The flu is often referred to as a respiratory illness; however, it can cause symptoms in a number of different parts of the body. Each person experiences the flu a bit differently, so it is common for two people infected with the same strain of the virus to have different symptoms.

People with the flu may experience the following symptoms:

• Fever or chills
• Fatigue or feelings of extreme tiredness
• Muscle or body aches
• Vomiting
• Diarrhea
• Nausea
• Stuffy nose
• Sore throat
• Runny nose
• Cough

Symptoms like nausea, diarrhea, and vomiting are more likely to occur in children than adults. Additionally, while a fever is one of the most well-known symptoms of the flu, not all people that get the flu will have a fever. Symptoms may range in severity from person to person.

How Do I Know If I Have the Flu?

Unfortunately, the only way to know for sure if you have the flu is to get tested by your doctor. That’s because many of the symptoms commonly associated with the flu are also signs and symptoms of other illnesses and are challenging to differentiate.

While some people attempt to use a fever to differentiate between the flu and other types of viral illnesses, identifying a fever is not a foolproof method because not everyone who has the flu will have a fever.

However,flu season most commonly occurs in the colder months of the year, including October through April in the northern hemisphere. While it is possible to get the flu at any time of year, if you are experiencing a number of the above symptoms during the colder months of the year, there is a good possibility you have the flu. The viruses that cause the flu cause the majority of illnesses during the colder months of the year.

The only way to know for sure that you have the flu is to get a test at your doctor’s office or clinic.

What Are the Different Types of Flu Tests?

There are several differentflu tests available, each of which works differently, has a different level of accuracy, and takes a different amount of time to produce results.

Rapid Influenza Diagnostic Tests (RIDTs)

The most common type of flu test is the rapid influenza diagnostic test, commonly referred to as RIDT. RIDTs provide results the fastest of any of the types of flu tests, with results available in just 10 to 15 minutes.

These tests work by detecting the presence of antigens, which is the portion of the virus that stimulates a defensive response from your immune system. While these tests produce quick results, they are not as accurate as other flu tests; it is possible to get a negative RIDT result and still have the flu.

Rapid Molecular Assays

Rapid molecular assays are another type of flu test that produces quick results. These tests, which work by detecting the presence of the genetic material that makes up the flu virus, are known to be more accurate than RIDTs. You’ll have to wait just a little bit longer – about 15 to 30 minutes – in order to get your results.

Other Assays

If you visit a hospital or a public health laboratory for your flu test, you may have access to other specialized tests that may provide accurate results. These tests, which include reverse transcription polymerase chain reaction (RT-PCR) tests and immunofluorescence assays, are the most accurate for detecting the presence of the flu and take anywhere from one hour to several hours to produce results.

In order to provide a sample for the test, the inside of your nose or the back of your throat is swabbed and the sample is sent for testing.

Viral Cultures

The use of viral cultures is not as common as other tests to test for the flu. Viral cultures involve growing the influenza virus in a laboratory, which can take around a week to get results. It can often be expensive to perform this type of test. However, viral cultures may be used to confirm a positive or negative result.

Are Flu Tests Accurate?

The accuracy of flu tests varies depending on several factors, the first of which is the type of test administered.

Rapid flu tests are most effective when used during a flu outbreak and they appear to be better able to detect the virus in children as compared to adults. However, the accuracy of flu tests can also vary depending on the strains of the flu that are circulating during any given year.

The flu mutates from year to year, and some tests are not as accurate at detecting new strains of the virus.

It is possible to receive a negative rapid flu test result and still have the flu. Based on your symptoms, your healthcare provider may diagnose you with the flu nonetheless, although you could also have one of many illnesses that causes similar symptoms.

Can the Flu Be Prevented?

While flu testing is available, by the time you have made it to the doctor’s office, your symptoms are likely pretty miserable. However, it is often possible to prevent or minimize your chances of contracting the flu by getting a flu vaccine and practicing basic hygiene.

The flu vaccine is developed every year based on information about which strains of the flu are the most likely to be circulating during the coming season. The flu vaccine varies in effectiveness from year to year, with prevention rates typically hovering around 40 to 60 percent.

Even if the vaccine does not stop you from getting the flu, it may be able to minimize your symptoms and lower your risk of experiencing any complications in the event that you do get infected. As a result, doctors recommend that everyone get their flu vaccine each year.

Another important defense against the flu is basic hygiene practices like regular handwashing, particularly after touching common surfaces such as a doorknob, kitchen counter, or credit card reader. Washing your hands with warm soap and water for 20 seconds is highly effective at removing the flu virus from your hands if you happen to have picked it up from a nearby surface.

Additionally, it’s important to minimize the time you spend around people who appear to be ill, and avoid eating or drinking using the same dishes and utensils as other people.

Summary

The flu is a highly contagious viral illness that causes symptoms like fever, sore throat, cough, runny nose, body aches, and headache. Because the symptoms of the flu can mimic those of other illnesses, it can be hard to know whether or not you actually have the flu or if you’re sick with a different illness.

If you visit the doctor for your symptoms, they may choose to test you for the flu. There are different types of testing for the flu available, including rapid influenza diagnostic tests (RIDTs), rapid molecular assays, and other tests, such as reverse transcription polymerase chain reaction (RT-PCR) tests, immunofluorescence assays, and viral cultures. Of these, the specialized tests are the most accurate, taking up to several hours to come back.

While test results from the rapid tests can be available in as little as ten minutes, these tests are not as accurate and may sometimes provide a false negative result.