Flu A vs Flu B, also known as influenza or flu, is a highly contagious respiratory disease usually caused by influenza viruses. It infects the throat and nose. In some cases, it affects the lungs.

Many people consider the flu a mild illness with a fairly quick recovery. For others, particularly seniors, the flu is a mild infection with severe symptoms and can be life-threatening. According to the CDC, over 41 million flu cases are reported each year. Approximately 710,000 cases of reported flu infections result in hospitalization, and 51,000 deaths occur.

Types of Flu

All flu viruses fall under four different categories. These include flu types A, B, C & D. You’ll most likely hear about flu types A and B during the flu season, which begins in October to May (the following year). Flu type C causes mild symptoms in people and isn’t linked to significant outbreaks. Flu type D doesn’t affect humans. It affects mainly cattle.

Differences between Flu A vs Flu B

Let’s focus on the two main types of flu – A and B. What are the main differences?

Flu A often accounts for the highest number of reported influenza illnesses compared to Influenza B. For example, flue type A accounted for about 96% of all influenza cases reported in the last quarter of 2024. Thus, flu type B isn’t as common as type A.

Another difference lies in how both influenza types attach to children. In kids, flu type A is linked to ear infections, while type B is linked to vomiting, diarrhea, and seizures. Note that the most important difference between flu type A and type B is that influenza B affects humans only, while A affects mammals and birds. This explains why antigenic shift occurs with flu A but not with type B.

Symptoms of Flu

You’ll feel lousy whether you have flu type A or B. Unlike the common cold, influenza symptoms will hit right away. Both flu A and B start with fever, and then the other symptoms follow. If you have the flu, you’re likely to have the following symptoms.

• Cough
• Headache
• Vomiting or diarrhea (especially in kids)
• Chills
• Sore throat
• Muscle aches
• Fatigue
• Stuffy or runny (congestion)

These flu symptoms can be mild or severe and vary from one patient to another. Other symptoms that aren’t common include shortness of breath, loss of consciousness, high fever, severe pain, seizures, and severe dizziness.

Flu Treatment

Healthcare providers often recommend the same treatment whether a patient has flu type A or type B. Some home remedies may relieve influenza symptoms. However, prescription antiviral medication may be more effective, especially for patients with severe symptoms or a higher risk of other health complications.