When you test positive for the flu, your results may say influenza A or influenza B. Many people wonder whether one type is worse than the other and whether it changes how they should be treated. Both types cause the familiar fever, body aches, cough, and exhaustion that can knock you off your feet for days.
Understanding the difference between flu A and B can help you know what to expect, who is most at risk, and when to seek care. If flu symptoms turn severe and you need the closest emergency room near me, Neighbors Emergency Center in Lubbock is open 24/7.
What Is Influenza?
Influenza is a contagious respiratory illness caused by influenza viruses. There are four types: A, B, C, and D. Types A and B cause the seasonal flu outbreaks that sweep across the United States every fall and winter. Type C usually causes mild illness, and type D mainly affects cattle.
What Is Influenza A?
Influenza A is the most common type of flu. It infects humans as well as animals such as birds and pigs. Influenza A viruses are divided into subtypes based on two proteins on their surface, hemagglutinin (H) and neuraminidase (N). Common subtypes include H1N1 and H3N2.
Because influenza A changes quickly and can jump between species, it is responsible for flu pandemics, including the 2009 H1N1 pandemic. According to the CDC, influenza A viruses are the only flu viruses known to cause pandemics.
What Is Influenza B?
Influenza B infects only humans. It is divided into two lineages, B/Victoria and B/Yamagata, rather than subtypes. Influenza B changes more slowly than influenza A, so it does not cause pandemics. However, it still causes seasonal outbreaks and can be serious, especially for children.
Key Differences Between Flu A And Flu B
- Hosts: Flu A infects humans and animals. Flu B infects only humans.
- How common: Flu A causes most flu cases each year. Flu B usually makes up a smaller share and often peaks later in the season.
- Mutation rate: Flu A changes faster, which makes it harder for the immune system to keep up.
- Pandemic risk: Only flu A can cause pandemics.
- Who it affects most: Flu A is often more severe in older adults. Flu B can hit children especially hard.
Symptoms Of Flu A And Flu B
The symptoms of both types are very similar, and you cannot tell them apart without a test:
- Fever and chills.
- Body aches: often severe.
- Cough and sore throat.
- Fatigue: that can last for days.
- Headache.
- Runny or stuffy nose.
- Vomiting and diarrhea: more common in children.
Is Flu A Or Flu B Worse?
In general, flu A is linked to more hospitalizations in adults, particularly older adults, because it spreads more widely and changes faster. However, flu B can be just as severe, and in some seasons it causes a large share of flu-related deaths in children. Both types deserve to be taken seriously.
How Flu A And B Are Diagnosed And Treated
A rapid flu test from a nasal swab can identify whether you have flu A or flu B, often within minutes. Treatment is the same for both types. Antiviral medicines such as oseltamivir (Tamiflu) and baloxavir (Xofluza) work against both and are most effective when started within 48 hours of symptoms.
Rest, fluids, and over-the-counter fever reducers help with symptoms. An er for flu visit is a good option when symptoms are severe or you are at high risk for complications.
When To Go To The ER
Call 911 or go to the ER right away if you have:
- Trouble breathing or shortness of breath.
- Chest pain or pressure.
- Confusion or trouble waking up.
- Seizures.
- Severe weakness or dehydration.
- Flu symptoms that improve, then return with a worse fever or cough.
In children, also watch for fast breathing, bluish lips, not drinking, or no tears when crying.
How To Protect Yourself
- Get a yearly flu shot: it protects against both flu A and flu B strains.
- Wash your hands often.
- Avoid close contact with sick people.
- Stay home when you are sick.
Key Takeaways
- Both are serious: flu A and flu B cause similar symptoms and can lead to complications.
- Flu A is more common: and is the only type that causes pandemics.
- Flu B can be severe in kids: and often peaks later in the season.
- Treatment is the same: antivirals work best when started early.
- Vaccination protects against both: get your flu shot every year.
Frequently Asked Questions
Can You Get Flu A And Flu B In The Same Season?
Yes. Because they are different viruses, having one does not protect you from the other.
Is Flu B Contagious?
Yes. Both flu A and flu B spread easily through coughs, sneezes, and contaminated surfaces.
How Long Does Flu A Or Flu B Last?
Most people recover in 5 to 7 days, though fatigue and cough can last up to two weeks.
Neighbors Emergency Center For Flu Care In Lubbock
Whether you have flu A or flu B, severe symptoms need prompt attention. Neighbors Emergency Center offers rapid flu testing, IV fluids, and breathing treatments for patients across Lubbock and the South Plains. Our emergency room lubbock families rely on is open 24/7. For life-threatening emergencies, call 911 right away.