Influenza

What is Influenza?

Influenza, commonly known as the flu, is a virus that targets the respiratory system, including the nose, throat and lungs. It is highly contagious and spreads through airborne droplets when someone who is infected coughs, sneezes or speaks. Flu season typically occurs in the fall and winter months, with peak activity between December and February.

While many people recover within a few days to two weeks, the flu can cause severe complications, especially in young children, older adults, pregnant women and those with chronic medical conditions.

Causes of Influenza

Influenza is caused by viruses that infect the respiratory system.

The two main types that affect humans are:

• Influenza A: The most common type, responsible for seasonal flu outbreaks and pandemics. It has many subtypes, including H1N1 and H3N2.
  
• Influenza B: Also causes seasonal flu but does not have subtypes like Influenza A. It is generally less severe but still leads to significant illness
  
  

Both types of flu viruses mutate frequently, which is why a new flu vaccine is needed each year.

Symptoms of Influenza

Flu symptoms usually appear suddenly and can vary in intensity from mild to severe. Common symptoms include:

• Fever or chills
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headache
• Fatigue
• Some people, especially children, may also experience vomiting and diarrhea
  
  

Symptoms typically last for about a week, though some people may feel tired for longer.

Diagnosing Influenza

Health care providers diagnose the flu based on symptoms and may confirm it with a rapid influenza diagnostic test (RIDT) or a PCR test. Testing is more common in high-risk individuals or during severe outbreaks.

Treatment for Influenza

Most people with the flu recover at home with rest and supportive care. However, antiviral medications can shorten the duration and severity of symptoms if taken within 48 hours of symptom onset.

Common treatments include:

• Rest and hydration: Drinking fluids and getting enough sleep help the body fight the infection.
• Over-the-counter medications: Non-prescription pain relievers such as ibuprofen or acetaminophen may help lower fever and ease body aches associated with the flu.
• Antiviral drugs: Prescription medications like Tamiflu (oseltamivir) or Xofluza (baloxavir marboxil) can help if taken early.
  
  

When to Seek Medical Care

Seek medical attention if you experience:

• Difficulty breathing or shortness of breath
• Persistent chest pain or pressure
• Confusion or dizziness
• Severe dehydration (little or no urination, dry mouth, dizziness)
• High fever

Prevention of Influenza

The best way to prevent the flu is by getting an annual flu vaccine. Additional prevention tips include:

• Wash hands frequently with soap and water.
• Cover coughs and sneezes with a tissue or your elbow.
• Avoid close contact with sick individuals.
• Clean and disinfect frequently touched surfaces.
• Stay home when feeling sick to prevent spreading the virus.

If you think you have the flu, rest, stay hydrated and monitor your symptoms. High-risk individuals should contact a doctor if symptoms worsen. Getting vaccinated each year is the best defense against influenza, helping to reduce illness and hospitalizations during flu season.

At Riverside Health, we're dedicated to compassionate, collaborative care. We provide a wide range of services, from childbirth to end-of-life care, delivering over 2 million services each year. Our integrated network allows us to support you seamlessly through health, illness, recovery, and wellness. With top clinicians and advanced technology, we’re here for you at convenient locations close to home and work. Visit riversideonline.com.

If you’re wondering where the best place is to get care, please see our guide below:

If your problem is life- or limb-threatening, call 911 or go to the emergency room.

Primary Care – Schedule through MyChart or call your provider’s office who you go to for most health care needs.

Virtual Clinic – Schedule through MyChart or click Here to learn more about Primary Care On Demand.

MD Express Urgent Care – Click Here to find a location near you for after-hours care or when your primary care provider is not available. Open 9am-9pm, Mon-Sun.

If you’re not sure, call Riverside Nurse 24/7 at 1-800-675-6368