The role of lab testing in managing seasonal illnesses like flu or strep throat
Medically reviewed by Dr. Betsy Koickel, MD on December 12th, 2025.
Seasonal illnesses like colds and the flu tend to spike during the colder months. Accurate and timely lab testing plays an important role in diagnosing these infections, guiding treatment and preventing further spread.
What are seasonal illnesses?
Seasonal illnesses are illnesses that happen at specific times of year, typically due to weather changes, humidity or human behavior. During colder months, for example, people spend more time indoors, allowing viruses and bacteria to spread more easily through close contact and shared air.
Common seasonal illnesses include the flu, strep throat, the common cold and respiratory syncytial virus (RSV). Although symptoms may overlap, identifying the specific cause is important for proper treatment, especially since bacterial infections like seasonal strep throat require antibiotics, while viral infections such as the flu do not.
Why does flu season occur?
In the United States, flu season starts in October and can last through May, with peak activity between December and February. Cold, dry air helps the flu virus survive longer in the environment, and indoor heating can dry out nasal passages, making it easier for viruses to enter the body.
According to the CDC, annual flu epidemics result in millions of infections and hundreds of thousands of hospitalizations. Getting vaccinated early can help reduce the spread and protect you from getting the flu.
Testing also plays a vital role in confirming a diagnosis, since flu symptoms can resemble those of other seasonal illnesses such as COVID-19 or strep throat.
Understanding seasonal strep throat
Seasonal strep throat refers to an increase in group A Streptococcus bacterial infections during colder months. Strep throat is contagious, as the bacteria spread easily through respiratory droplets when an infected person coughs or sneezes.
How lab testing helps in diagnosing strep throat
Symptoms of strep throat, such as sore throat, fever, and swollen lymph nodes, can look similar to other viral infections, making lab testing essential for accurate diagnosis.
Rapid strep tests can be done quickly in a provider’s office or urgent care. These tests detect bacterial proteins (antigens) in just minutes using a throat swab. If results are inconclusive, your healthcare provider may request a throat culture, which can take a few days, as they can identify even low bacterial counts.
Accurate testing ensures that you will receive antibiotics only when necessary, helping prevent complications and lowering the risk of antibiotic resistance.
The importance of lab testing for flu season
Because flu season overlaps with an increase in other respiratory illnesses, distinguishing between conditions is difficult based on symptoms alone.
Flu testing can help confirm infection, so antiviral medication can be started if appropriate. Testing can also help prevent unnecessary antibiotic use if the illness is confirmed to be the flu, which is caused by a virus and cannot be treated with antibiotics.
Lab testing can also help public health officials track seasonal trends, so they can make important public health decisions.
During flu season, early testing and treatment can help reduce the severity of symptoms, shorten illness duration and prevent complications, especially in at-risk populations such as children, older adults and those with chronic conditions.
How lab testing helps manage seasonal illnesses
Lab testing is an important part of effective seasonal illness management. By identifying the specific virus or bacteria causing symptoms, providers can more easily prescribe targeted, effective treatment to help you feel better faster.
It can also help reduce the overall spread by confirming and treating contagious cases. This can help contain outbreaks in communities and allow public health professionals to make more informed decisions.
Urgent care centers offer rapid flu and strep testing with results during the same visit, helping providers make quick treatment decisions so you feel better faster. To get started, find a center near you and walk in or save your spot online.
FAQs
Here are some frequently asked questions about seasonal illnesses.
How does lab testing help in diagnosing seasonal illness?
Lab tests identify whether your symptoms are caused by a virus or bacteria, helping guide appropriate treatment and preventing unnecessary antibiotics.
What are the symptoms of seasonal strep throat, and how do lab tests help?
Symptoms include sore throat, fever, red tonsils and swollen lymph nodes. A rapid strep test confirms the cause, so the right antibiotics can be prescribed.
Why should I get tested for flu during flu season?
Flu symptoms can overlap with other illnesses. Testing confirms your diagnosis so your healthcare provider can prescribe the correct treatment and you can avoid spreading infection.
When is flu season, and why does it matter for diagnosis?
Flu season typically runs from October through May. Testing during this period is especially important since flu activity is highest, and early detection can help prevent complications.
What’s the difference between flu and strep throat symptoms?
Flu often causes fever, fatigue, cough and body aches, while the main symptom of strep throat is severe throat pain and swollen glands without coughing.
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