Influenza or flu is an illness caused by the influenza virus. It results in symptoms such as body and headaches, respiratory issues, fever, and sore throat, which can be severe. This condition is most prevalent during winter. It is also called the flu season due to the spike in flu cases. Influenza is one of the most common infectious diseases; therefore, understanding the causes and warning signs of the condition is important for effective management.

Causes and risk factors

The influenza virus travels via air droplets when someone with an infection sneezes, talks, or coughs. You can inhale the virus directly or pick the germs from an object like a computer keyboard or a telephone and transmit them to your mouth, nose, or eyes. People who catch the virus are transmissible from the day before the symptoms show to four days after they appear. However, people, especially children with weak immune systems, are contagious for a relatively longer duration.

Influenza A, B, and C are the most common forms of the virus that infect individuals. Influenza A and B are more prevalent during winter, while Influenza C isn’t seasonal.

Influenza viruses keep evolving, with newer strains appearing regularly. People who had influenza in the past form antibodies that help combat the specific virus strain. However, the antibodies may decline with time. Furthermore, antibodies acquired from specific influenza virus strains in the past may not guard a person against the new strains.

Besides the above-listed causes, some risk factors amplify one’s risk of developing influenza. These include:

1. Age – Seasonal flu has more severe outcomes in children below two and adults over 65.
2. Pregnancy – Pregnant women are at an increased risk of getting influenza symptoms, especially in the third or second trimesters. The risk continues for approximately two weeks post the baby is born.
3. Weakened immune system – Anti-rejection treatments, cancer therapies, organ transplants, HIV/AIDs, or blood cancer weakens your immune system, increasing the risk of contracting the flu.
4. Working or living conditions – People residing or working in facilities with several other residents, like nursing homes, are more susceptible to developing flu.
5. Chronic illnesses like lung diseases, asthma, nervous system conditions, heart diseases, diabetes, issues with the airway, metabolic disorders, and blood, liver, or kidney diseases also worsen influenza risk.

Symptoms

Most symptoms of the condition go away in four days to a week. Some common warning signs of influenza include-

1. Stuffy or runny nose
2. Body aches
3. Chills
4. Fever
5. Sore throat
6. Vomiting or diarrhea
7. Fatigue
8. Headache

However, an individual may have one or a combination of the above-listed symptoms if they have the flu.

Prevention

Some preventive measures to lower the risk of catching influenza are listed below.

1. Not touching your mouth, nose, or eyes too often
2. Cleaning your hands regularly
3. Covering one’s nose and mouth when sneezing or coughing
4. Staying at home while sick
5. Avoiding close contact with sick people

A healthcare professional will suggest a physical examination to diagnose the flu. Treatments for the condition aim to manage the symptoms, facilitate early recovery, and prevent severe complications like pneumonia. If left untreated for long, flu can lead to more severe health complications such as inflammation of the heart and multi-organ failure.