What is Influenza Infection?

Influenza infection, also known as the flu, is a common viral infection of the airways that most often occurs in fall and winter. It can cause multiple symptoms, including fever, cough, a runny nose, and muscle aches.^[1]

Influenza can be caused by a number of different viruses and is spread from person to person, primarily through sneezing and coughing.^[2] When an infected person sneezes, coughs, or talks, they may send infected water droplets into the air. It is then possible for a nearby person to inhale these and contract the infection themselves. It is also possible to catch influenza indirectly by touching a contaminated surface or object and then touching the eyes, nose, or mouth.^[3]

Because influenza is so infectious, people with mild cases of the flu are recommended to avoid contact with others by staying at home during their illness. In most cases, no specific treatment is needed, and people recover from flu within a week.^[4]

However, people with severe cases of the infection, or who are at higher risk of developing flu-related complications, may need to seek medical attention.^[5] In rare instances, influenza can cause severe complications, in which case the condition may become life-threatening.

Types of influenza infection

There are two main types of influenza infection that affect humans, known as influenza A and influenza B. These two viruses are responsible for the majority of seasonal flu epidemics that break out each year, with most cases occurring during the winter period.^[6]

Influenza A is believed to cause more than 70 percent of flu cases in a typical season. Of the remaining 30 percent of flu cases, the majority are caused by influenza B.^[7] Both types of the virus result in similar flu symptoms.

The viruses that cause influenza A are constantly evolving, meaning that new strains of the infection develop fairly often.^[5] The influenza B virus is also able to develop over time, although at a slower rate than influenza A.

Because the viruses are constantly changing, it is possible to contract influenza infection multiple times in a lifetime. Falling ill with one strain of the flu may help to build immunity against that particular strain, but it is unlikely to protect against a different strain in the future.^[8] Annual flu shots are typically updated every year in order to vaccinate against the influenza strain, or strains, that is/are expected to be most common that year.^[9]

Good to know: There are two further types of influenza virus: influenza C and D. However, influenza type C occurs much less frequently in humans and only causes a mild respiratory illness. Influenza type D mostly affects cattle and is not known to infect humans at all.^[10]

Influenza infection symptoms

Influenza infection can cause mild to severe symptoms that are variable from person to person. Symptoms can come on very suddenly and most often begin to appear one to four days after infection.^[4] However, in some cases, the onset of influenza symptoms can occur a matter of hours after exposure.^[11]

Common symptoms of influenza infection

Typical signs and symptoms of influenza infection include:^{[1][5][7][12]}

• High fever or feeling feverish
• Dry cough
• Sore throat
• Headache
• Cold-like symptoms, such as a runny nose and watery eyes
• Muscle and joint aches
• Fatigue and feeling weak
• Feeling generally unwell

Respiratory symptoms, such as coughing and a sore throat are often minimal at first, but can develop to become more prominent as the infection progresses.^[9] Vomiting and diarrhea may also be present; this is more common in children than adults.^[12]

The severity of many symptoms can range from mild to severe. For example, while a fever is a common symptom of influenza infection, it might be a low fever of around 100 F / 37.7 C or a high fever of around 104 F / 40 C. Other people with influenza infection may simply feel feverish, without displaying a high temperature at all.^[13]

Symptoms usually peak within the first couple of days of their onset and then begin to subside. Coughing, weakness and tiredness are often the final symptoms to disappear. Most people with an influenza infection recover within a week.^[9]

Symptoms of severe influenza infection

While unpleasant, typical flu symptoms do not usually require medical intervention.^[14] However, there are a number of additional symptoms which may indicate a more serious infection or the presence of a flu-related complication, such as pneumonia. Symptoms that may be a warning sign of severe influenza sickness include:^[14][15]

• Shortness of breath or fast breathing
• Increased heart rate
• Chest or abdominal pain
• Recurrent high fever
• Dizziness
• Confusion

In children, additional symptoms may include:

• Trouble breathing
• Bluish tinge to the skin
• Inability or unwillingness to eat or drink
• Fever with a rash

Such symptoms may be an indication of more serious influenza infection or of a flu-related complication. People who are exhibiting more severe influenza infection symptoms should seek medical attention.

Flu vs. cold

It can be difficult to tell the difference between influenza infection and the common cold. Both are respiratory illnesses that often cause similar symptoms, such as coughing, sneezing, and a sore throat. However, identifiable differences to look out for include:^[16]

• Flu symptoms are usually more intense than cold symptoms
• Flu symptoms tend to arrive quickly, whereas cold symptoms appear more gradually
• Fever and headaches are common symptoms of flu, but are rare with colds
• Flu can cause more serious complications, such as pneumonia. It is not usual for a cold to result in any other health problems

If you are concerned you may have an influenza infection or a cold, contact your doctor Find My doctor’s location to begin your personal health assessment.

Causes of influenza infection

Influenza infection is caused by an influenza virus. It is a highly contagious infection that can affect anyone. Because it is such a common condition, exact data on how many people contract the flu each year is not readily available. However, the Centers for Disease Control and Prevention estimate that the flu has caused between 9.3 million to 49 million illnesses annually in the United States since 2010.^[17]

Influenza infection is usually contracted through the inhalation of contaminated water droplets. Often, these water droplets are released through the nose or mouth of an infected person. Three common ways in which the virus is spread are:^[3][9]

• Airborne droplets. When an infected person coughs, sneezes or talks, they can release water droplets into the air. These airborne droplets may then be inhaled by another person
• Direct contact. Direct contact with the water droplets of an infected person, e.g. sharing household utensils or kissing
• Indirect contact. Handling an object or surface which has been contaminated with the influenza virus, e.g. touching a used tissue

Good to know: It is very unusual for humans to contract influenza infection direct from animals. When transmission does occur, it is predominantly the result of direct contact with infected animals, e.g. through farming, slaughter, food preparation, exposure to water contaminated by droppings.^[18][19]

Risk factors for influenza infection

Although anybody can contract influenza infection, the majority of people with the illness are able to recover at home without the need for hospitalization or medical care. Most affected people make a full recovery within a week.^[4]

However, there are certain groups of people who are at higher risk of developing flu-related complications. Such groups include:^{[5][7][1][20]}

• Adults over the age of 65
• Children under the age of five, in particular under the age of two
• People living in closed environments such as nursing homes or other care facilities
• Pregnant people and people up to two weeks after giving birth
• Native Americans
• People with certain pre-existing medical conditions

Medical conditions which may increase the risk of flu-related complications developing include:^{[1][5][7][20][21]}

• Asthma
• Diabetes
• Heart diseases, such as heart failure and coronary artery disease
• Lung conditions, such as cystic fibrosis and bronchitis
• Kidney problems, such as chronic nephritic syndrome
• Liver disorders, such as hepatitis and cirrhosis
• Severe anemia
• Severe obesity, classified with a Body Mass Index (BMI) of 40 or higher
• Medical conditions or treatments that can result in a weakened immune system, such as HIV infection or chemotherapy

Good to know: In the United States, the flu season is considered to take place during fall and winter, with incidences commonly peaking between December and February.^[17][22] People located in the Northern Hemisphere are therefore at higher risk of contracting influenza infection during these months, although infection can occur at any time of the year. The Southern Hemisphere also typically experiences a winter flu season, which usually takes place between April and September.^[23]

Diagnosing influenza infection

Diagnosis of influenza infection is usually based on the symptoms experienced and an evaluation by a doctor. Diagnosis may be particularly swift if there is a known presence of a flu outbreak in the local community. Further tests are often not necessary because a clinical evaluation is usually enough to recommend a course of treatment.^[24]

However, further diagnostic tests may be recommended if:

• Diagnosis is uncertain
• Symptoms are severe
• The affected person is at higher risk of developing complications
• An outbreak of respiratory illness has occurred in the local community, and the test may be able to confirm flu as the cause

Two common tests used to help diagnose influenza infection are rapid influenza diagnostic tests (RIDTs) and rapid molecular assays. Both tests involve swabbing a person’s nose or throat and testing the mucus for the virus. Results can often be produced within 20 minutes. However, while the tests are quick and simple to perform, results are not as accurate as other diagnostic methods. It is possible to still receive a flu diagnosis, even with a negative test result.^[24]

Despite their limitations, the speed and simplicity of RIDTs can make them useful in promptly identifying influenza as the cause of a respiratory disease outbreak, particularly in care settings such as hospitals and nursing homes. If RIDTs confirm positive results in one or more people with suspected influenza, a swift decision can then be made to implement infection control measures and administer treatment.[^46]

Blood tests may be suggested if further complications are suspected.^[5] If the person is thought to have developed pneumonia or is displaying significant respiratory problems, a chest X-ray may also be conducted.^[9]

Good to know: Because influenza infection is so common, it is often correctly suspected by the affected person before medical diagnosis takes place.^[7] Many people, therefore, choose to stay at home and wait for the infection to pass of its own accord. However, if the affected person is worried about their symptoms, is very sick, or is in a high-risk group for developing complications, medical care should be sought.^[14]

Worried that you or a loved one may have an influenza infection? check a List of Doctors to begin your personal health assessment.

Treatment of influenza infection

There is no specific medication used to target the influenza virus itself. Instead, treatment aims to manage and ease the symptoms of influenza, until the body’s natural immune system is able to clear the infection.^[7]

At-home treatment

Most people are able to recover from influenza infection at home, without the need for medical intervention.^[2] Home remedies that may help manage the symptoms of influenza include:^[5][7][25]

• Staying hydrated by drinking lots of fluids, such as water
• Resting and avoiding strenuous activities
• Reducing fever and aches with acetaminophen, or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen
• Reducing cold-like symptoms, such as a runny nose and sore throat, with common cold treatment methods such as nasal decongestants and oral lozenges

Good to know: Although aspirin can be used to reduce fever and aches, it is not recommended for use by children or adolescents under the age of 18. This is because of the risk of a rare but serious condition called Reye’s syndrome, which can result in liver and brain damage.^[26] Acetaminophen and ibuprofen are generally used as suitable alternatives.

Antiviral medication

People with a severe case of the flu, or those who are at greater risk of developing complications, may be prescribed antiviral medications by their doctor.^[5] People who are at high risk of developing complications may also be prescribed antiviral medication as a preventive measure, in order to reduce the risk of contracting the flu altogether.^[27]

The most common antiviral medications used are:^[7][28]

• Oseltamivir, typically swallowed as a pill or liquid
• Zanamivir, typically inhaled as a powder
• Peramivir, typically injected as a liquid

These medications target both influenza type A and type B. They do not kill the virus, but they can lessen the symptoms and shorten the period of illness by a couple of days.^[29]

Antiviral drugs are also used to reduce the risk of the affected person developing complications. These drugs are most effective when used within the first 48 hours of symptoms first appearing.^[5]

Good to know: Because influenza infection is viral and not bacterial, antibiotics are not effective in treating the illness. However, antibiotics may be prescribed if the affected person develops an additional bacterial infection as a complication of influenza.^[7]

Preventing influenza infection

The best precaution against influenza infection is to be vaccinated against it.

Flu vaccine

Centers for Disease Control and Prevention (CDC) recommends annual flu vaccination for all people in the U.S. over the age of six months old.^[30] It is considered the best way to help prevent seasonal flu and its potential complications. The flu vaccine is especially important for people who are at higher risk of developing flu-related complications, such as the elderly or people with certain medical conditions.

Vaccinations are updated on an annual basis, in order to protect against the most prevalent strains of the influenza virus that year.^[9] It is recommended that people receive a flu vaccine in early fall before the flu season begins.^[17] The two main vaccination methods are:^[7]

• Flu shot. An injection is the more common vaccination method and can be given to anyone aged six months or over, including pregnant people. People over the age of 65 may receive a slightly higher dose of the vaccine.
• Flu nasal spray. This vaccination method is typically reserved for otherwise healthy people between 2 to 49 years old. It is not suitable for certain people, including pregnant people, those with a weakened immune system, children under the age of 18 who take long-term aspirin medication or asthmatic children aged between two to four years old.

Good to know: Most people are able to receive one of the above flu vaccination methods. However, there are multiple vaccination options, and talking to a doctor can be useful to help people decide which is the best option for them each year.

Flu vaccine benefits

Vaccination against the flu has multiple benefits, including:^[31]

• Preventing influenza infection. Centers for Disease Control and Prevention estimates that flu vaccination prevented around 5.3 million influenza illnesses in the United States during 2016-2017^[32]
• Preventing influenza-related hospitalization. A 2017 study found that the vaccination in the United States reduced the number of adult flu-related hospitalizations by an average of around 40 percent^[33]
• Reducing the severity of influenza infection. In the United States, flu vaccination has resulted in reduced flu-related deaths, intensive care admissions and hospitalization duration, according to one 2017 study^[34]
• Life-saving in children. A Centers for Disease Control and Prevention study in 2017 was the first of its kind to show that a flu vaccination can significantly reduce the a child’s risk of dying from influenza infection^[35]

Good to know: In addition to the above benefits, receiving the flu vaccine also helps to protect other people in the community, including those who are at greater risk of developing the serious flu-related illnesses.^[32]

Isolation

Due to how contagious influenza viruses are, it is important to limit the risk of spreading the infection to others. For this reason, people with the flu are recommended to stay at home until around five to seven days after first becoming ill. Children and people with a weakened immune system can take longer than seven days to recover from the illness and therefore may remain infectious for longer.^[3]

As flu symptoms often only appear a couple of days after becoming infected, it is possible for a person to pass on the flu virus before realizing they themselves are infected. It is also possible to contract the flu but display no symptoms, however, these people are still able to spread the infection to others.^[5]

Hygiene

Practicing good personal hygiene can also help prevent the spread of influenza infection. Useful preventative measures include:^[14]

• Washing hands frequently, ideally with soap and water, or hand sanitizer
• Covering the mouth and nose with a tissue when coughing or sneezing
• Avoiding close contact with people who are sick
• Avoiding contact with the eyes, nose or mouth unless hands are fully clean

Preventive antiviral medication

As well as being used to treat an influenza infection, antiviral medication may occasionally be prescribed as a preventive measure to reduce the likelihood of a high-risk person contracting the condition and developing influenza-related complications.^[27] This preventive approach is known as prophylaxis.

Because the flu vaccine is considered to be the best precaution against influenza infection, antiviral prophylaxis is usually considered only in specific circumstances. Typically, it is only suggested to high-risk people who have been exposed to another person with influenza, and also fall into certain categories, such as:^[27]

• They received the flu vaccine within the last two weeks
• They cannot receive the flu vaccine, e.g. due to an allergy
• They may not be responsive to the flu vaccine, e.g. people receiving immunosuppressive medications

Antiviral prophylaxis may also be used to control an influenza outbreak among high-risk people in long-term care facilities, such as nursing homes. In such cases, antiviral medication may be prescribed to both residents and staff.^[27]

Complications of influenza infection

While the majority of people who contract influenza infection make a full recovery, complications can occur sometimes. Complications are more likely to develop in certain groups of people, as outlined in the risk factors section above.

Some complications can develop to become severe or even life-threatening. Pneumonia is a particularly common and serious potential complication of the flu.^[12] At-risk groups of people, such as the elderly, or those with certain pre-existing medical conditions, should contact a doctor if flu is suspected in order to limit the risk of developing a flu-related complication.

Moderate influenza complications

Moderate complications that can arise from influenza infection include:^[5][12][15]

• Sinus infection, also known as sinusitis
• Certain types of ear infection, such as acute otitis media
• Young children may experience fits caused by the fever, known as febrile seizures

Moderate complications are generally not thought to cause any long-term health problems, although some may require additional medical treatment.

Severe influenza complications

There are a number of severe complications that can develop through having influenza. Pneumonia is the most common complication of influenza infection, which can develop to become a potentially life-threatening condition.^[7]

Pneumonia and influenza

Pneumonia is a serious infection of the lungs and a common complication of influenza. Flu-related pneumonia can either develop as a direct result of the influenza virus, known as primary viral pneumonia or, more commonly, due to a combination of the virus and an added bacterial infection, such as bacterial bronchitis. This is known as secondary bacterial pneumonia.^[5]

Symptoms that may indicate the development of either primary viral or secondary bacterial pneumonia, include:^[7][15][16]

• Shortness of breath
• Fast breathing
• Increased heart rate
• Chest pain
• Recurrent high fever
• A deep, wet cough that produces mucus or phlegm, rather than the dry cough that is a common symptom of influenza
• Bloody phlegm

Good to know: Around 90 percent of acute bronchitis cases in otherwise healthy adults are caused by viruses, such as influenza.^[36]

Other severe complications

Other potentially severe complications of influenza infection include:^{[5][9][12][37]}

• An inflammation of the muscles, known as myositis
• An inflammation of the heart muscle, known as myocarditis
• An inflammation of the brain, known as encephalitis
• Sepsis
• Worsening of certain existing medical conditions, such as asthma or chronic heart failure

Good to know: Medical help should be sought by anyone who is worried they may have developed a complication due to influenza infection, whether moderate or severe. contact your doctor Find My doctor’s location.

Influenza infection FAQs

Other names for the influenza infection

• Flu
• Seasonal flu
• Grippe

---

1. Medscape. “Influenza.” 26 October 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩

2. MedlinePlus. “Flu.” 4 October 2017. Accessed 2 January 2019. ↩ ↩

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4. Patient. “Influenza and Flu-like Illness: Flu symptoms.” 25 September 2017. Accessed 2 January 2019. ↩ ↩ ↩

5. Amboss. “Influenza (Flu).” 28 December 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩

6. Centers for Disease Control and Prevention. “Influenza (Flu) Viruses.” 13 August 2018. Accessed 2 January 2019. ↩

7. MSD Manual. “Influenza (Flu).” September 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩ ↩

8. Centers for Disease Control and Prevention. “Misconceptions about Seasonal Flu and Flu Vaccines.” 25 September 2019. Accessed 2 January 2019. ↩

9. MSD Manual. “Influenza.” June 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩ ↩ ↩ ↩

10. Centers for Disease Control and Prevention. “Types of Influenza Viruses.” 27 September 2017. Accessed 2 January 2019. ↩ ↩

11. US National Library of Medicine. “Incubation periods of acute respiratory viral infections: a systematic review.” May 2009. Accessed 1 February 2019. ↩

12. Centers for Disease Control and Prevention. “Flu Symptoms & Complications.” 18 September 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩ ↩

13. Medscape. “Influenza Clinical Presentation.” 26 October 2018. Accessed 2 January 2019. ↩

14. Centers for Disease Control and Prevention. “The Flu: What To Do If You Get Sick.” 9 March 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩

15. Patient. “Influenza and Flu-like Illness: Complications of flu.” 25 September 2017. Accessed 2 January 2019. ↩ ↩ ↩

16. Centers for Disease Control and Prevention. “Cold Versus Flu.” 18 September 2018. Accessed 2 January 2019. ↩ ↩

17. Centers for Disease Control and Prevention. “Frequently Asked Flu Questions 2018-2019 Influenza Season.” 6 December 2018. Accessed 2 January 2019. ↩ ↩ ↩ ↩ ↩

18. Centers for Disease Control and Prevention. “Influenza in Animals.” 27 September 2018. Accessed 2 January 2019. ↩

19. World Health Organisation. “Influenza at the human-animal interface.” 25 July 2017. Accessed 2 January 2019. ↩

20. Centers for Disease Control and Prevention. “People at High Risk of Developing Serious Flu-Related Complications.” 27 August 2018. Accessed 2 January 2019. ↩ ↩

21. American Lung Association. “Flu Symptoms, Causes, and Risk Factors.” 17 August 2018. Accessed 2 January 2019. ↩

22. Centers for Disease Control and Prevention. “Current & Past Flu Seasons.” 10 August 2018. Accessed 2 January 2019. ↩

23. Centers for Disease Control and Prevention. “Influenza Prevention: Information for Travelers.” 31 July 2018. Accessed 1 February 2019. ↩

24. Centers for Disease Control and Prevention. “Diagnosing Flu.” 23 February 2018. Accessed 2 January 2019. ↩ ↩

25. Patient. “Influenza and Flu-like Illness: Flu treatment.” 25 September 2017. Accessed 2 January 2019. ↩

26. MSD Manual. “Reye Syndrome.” September 2017. Accessed 2 January 2019. ↩

27. Centers for Disease Control and Prevention. “Influenza Antiviral Medications: Summary for Clinicians.” 27 December 2018. Accessed 1 February 2019. ↩ ↩ ↩ ↩

28. MedlinePlus. “Peramivir Injection.” 15 June 2018. Accessed 2 January 2019. ↩

29. Centers for Disease Control and Prevention. “Flu Treatment.” 1 October 2018. Accessed 2 January 2019. ↩

30. Centers for Disease Control and Prevention. “Children & Influenza (Flu).” 8 November 2018. Accessed 1 February 2019. ↩

31. Centers for Disease Control and Prevention. “Get Vaccinated.” 31 August 2018. Accessed 2 January 2019. ↩ ↩

32. Centers for Disease Control and Prevention. “What are the benefits of flu vaccination?” 6 November 2018. Accessed 2 January 2019. ↩ ↩

33. US National Library of Medicine. “Effectiveness of influenza vaccines in preventing severe influenza illness among adults: A systematic review and meta-analysis of test-negative design case-control studies.” 18 September 2018. Accessed 2 January 2019. ↩

34. Centers for Disease Control and Prevention. [“New CDC Study Shows Flu Vaccine Reduces Severe Outcomes in Hospitalized Patients.”](https://www.cdc.gov/flu/spotlights/vaccine-reduces-severe-outcomes.htm] 25 May 2017. Accessed 2 January 2019. ↩

35. Centers for Disease Control and Prevention. “CDC Study Finds Flu Vaccine Saves Children’s Lives.” 4 April 2017. Accessed 2 January 2019. ↩

36. US National Library of Medicine. “Acute bronchitis.” February 2008. Accessed 1 February 2019.
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37. Patient. “Influenza: Complications.” 19 November 2015. Accessed 2 January 2019. ↩

38. US National Library of Medicine. “Rash, an uncommon but existing feature of H1N1 influenza among children.” 9 February 2011. Accessed 2 January 2019. ↩

39. US National Library of Medicine. “Case series of rash associated with influenza B in school children.” 10 November 2014. Accessed 2 January 2019. ↩

40. Arizona Department of Health Services. “Is It Influenza or Could It Be Measles?” 17 November 2014. Accessed 2 January 2019. ↩

41. Centers for Disease Control and Prevention. “New CDC Study Compares Severity of Illness Caused by Flu A and B Viruses.” 2 May 2014. Accessed 2 January 2019. ↩

42. Centers for Disease Control and Prevention. “Principles of Epidemiology in Public Health Practice (Section 11: Epidemic Disease Occurrence).” 18 May 2012. Accessed 2 January 2019. ↩ ↩

43. Centers for Disease Control and Prevention. “Pandemic Influenza.” 24 October 2018. Accessed 2 January 2019. ↩

44. Centers for Disease Control and Prevention. “Past Pandemics.” 10 August 2018. Accessed 7 January 2019. ↩

45. US National Library of Medicine. “Influenza Pandemics of the 20th Century.” January 2006. Accessed 2 February 2019. ↩

46. Centers for Disease Control and Prevention. “Highly Pathogenic Asian Avian Influenza A(H5N1) Virus.” 12 December 2018. Accessed 2 February 2019. ↩

## What is ⁤Influenza ⁣Infection?



**Overview**



Influenza is a⁢ highly contagious respiratory⁤ infection caused ⁣by the influenza virus. It affects‍ the nose, throat,⁢ and lungs, leading to a wide range‍ of​ symptoms. The influenza ⁤virus is transmitted‌ primarily through respiratory droplets ⁣from infected individuals⁤ when they cough, ‍sneeze, or talk.



**Symptoms**



The symptoms ⁤of influenza infection ⁤typically ⁢appear within 1-4 days of‌ exposure to the virus ⁣and​ can range from mild to ⁢severe:



* **Common:** Fever,⁣ chills, headache, muscle ​aches, fatigue, sore ⁣throat, dry‍ cough

* **Less common:** Runny nose, congestion, ​shortness of breath, nausea, vomiting, diarrhea



**Transmission**



Influenza is‍ spread through respiratory droplets that are released into‌ the air when⁢ an infected⁣ person coughs, sneezes,​ or talks. These droplets can land in the mouth or ⁣nose of ⁢nearby⁢ individuals, ‍leading to infection. The virus can also be transmitted by touching contaminated surfaces ​or objects ⁢and then‍ touching one’s face.



**Complications**



In severe cases, influenza infection can ‍lead ⁤to complications such as pneumonia, bronchitis, and hospitalization. These complications are⁢ more ‍common in individuals with ⁤underlying health conditions such as ‌asthma, heart disease, and ⁤weakened immune ​systems.



**Treatment**



There is no cure for influenza infection, but ‌treatment ⁢options ⁢are available to relieve symptoms and ⁣prevent complications. Medications such as antiviral drugs, pain relievers, and cough ​suppressants can be used to alleviate symptoms. In some cases, hospitalization ‌may be⁣ necessary for severe infections.



**Prevention**



The best ⁤way to prevent influenza⁣ infection is through vaccination. The annual influenza vaccine provides protection against the most ​common influenza viruses‌ circulating in ‍the season. Other preventive measures ⁣include:



* **Hand⁣ hygiene:** Washing hands frequently with soap and water ‌or using hand‍ sanitizer.

* **Respiratory hygiene:**⁤ Covering mouth and nose when coughing or‍ sneezing with a tissue or elbow.

* **Avoiding ⁢contact with ⁢infected individuals:** Staying home if you’re sick and avoiding⁢ close ​contact with infected people.

* **Disinfecting surfaces:** Cleaning and disinfecting⁣ surfaces that could be contaminated with the influenza virus.



**Key Points**



* Influenza is a highly contagious respiratory ⁢infection caused ‌by ‍the influenza virus.

*‌ Symptoms range​ from mild to⁣ severe and include ⁢fever, chills, aches, sore throat, and cough.

* Transmission occurs through respiratory droplets when infected individuals cough, sneeze, or talk.

* Vaccination is the best way to prevent influenza infection.

* Treatment options focus on relieving symptoms and preventing complications.