Seasonal Influenza: Causes, Symptoms, and Treatment

What is Seasonal Influenza?

Seasonal Influenza or Flu is a respiratory illness due to the attack of a virus in the nose, throat, and lungs. It is not the same as other flu infections that cause diarrhea and vomiting. Generally, influenza/flu will cure on its own but sometimes, they can become worse and potentially fatal.

What causes Seasonal Influenza

Seasonal influenza is a droplet infection (infection transmitted from one individual to another through droplets of moisture from the upper respiratory tract by sneezing or coughing). People with poor immune systems are likely to catch the flu easily.

The influenza virus changes constantly with new strains appearing regularly. If you are attacked by influenza in the past, your body develops antibodies to fight against the strains of the virus. Therefore, if influenza attacks you again, the previously produced antibodies will fight against the infection and lessen the severity. But if the strains are different than the previous one, antibodies cannot fight against the new strains.

Signs and Symptoms of Seasonal Influenza

People affected with seasonal influenza – initially experience a common cold associated with running nose, sneezing, and sore throat. Later, chills may also develop and there can be sudden flu attacks.

Other common symptoms include:

1.High fever

2.Muscle pain

3.Chills and sweats


5.Dry cough

6.Fatigue and weakness

7.Nasal congestion

8.Sore throat

Risk Factors:

1.Age: It easily attacks children younger than 12 years and elders above 65 years of age.

2.Living or Working Environment: People who live in crowded areas such as nursing homes or military houses are likely to develop influenza symptoms and also people who are hospitalized are at higher risk.

3.Poor Immune System: Patients with cancer, organ transplant, blood cancer, or HIV/AIDS have a weak immune system. Hence, they can easily develop influenza and associated complications.

4.Chronic Diseases: Chronic diseases related to lungs, asthma, diabetes, heart disease, neurological or developmental diseases, kidney, liver, and blood diseases may increase the risk of complications.

5.Long Term Use of Aspirin: People younger than 19 years; people who are addicted to long term use of aspirin are at risk of developing Reye’s syndrome if infected with influenza.

6.Pregnancy: During pregnancy or after pregnancy, women are more likely to develop influenza symptoms, especially during their second and third trimesters.

7.Overweight: People who are obese or who have a body mass index (BMI) of 40 are more prone to develop influenza symptoms.

How long does it stay?

For healthy individuals, seasonal influenza is not serious, it generally goes away within 7-14 days with no lasting effects. But children and aged people may have complications which include:

Pneumonia, a most serious complication

Asthma flare

Heart problems

Infection of the ear

When should I See a Doctor?

Mostly the flu will cure on its own. If the symptoms are severe and bother you much, see your doctor right away, your physician may suggest antiviral drugs that will reduce the illness and help to prevent the severe complications.


CDC (Centre for Disease Control and Prevention) recommends an annual flu vaccine for babies, children, and adults. Note that this is suitable for babies above 6 months only.

Preventive measures to control the spread of Influenza Infection

1. Follow Good Hygiene: Personal hygiene and frequent hand wash after contact with objects or after playing with pets may help to reduce the chances of the infection spreading. Also, use alcohol-based hand sanitizer if soap and water are not readily available.

2. Cover your Nose and Mouth: Cover your nose and mouth when you sneeze or cough to avoid the spread of infection or to prevent the contamination and spread of influenza.

3. Avoid Going to Crowdy Areas: Flu easily spreads in a crowded area or spread through droplet infection by touching the objects contaminated with the virus. Therefore, it is better to stay away from crowded areas. In case if you are infected, isolate yourself till you recover, in this way there are fewer chances of infecting others.

Written by MedPlus