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Unravelling the Causes of the Flu: From Symptoms to Seasonal Changes

Reviewed by Getadoc Team5 min read Updated 11 July 2026
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Flu, scientifically known as Influenza, is a common ailment that affects millions of South Africans annually. From sudden changes in the weather to the transmission of the virus, various factors come into play. This article demystifies the causes of flu and offers a comprehensive understanding of the symptoms associated with this ailment.

What is Influenza?

Influenza, more commonly called the flu, is a contagious viral infection affecting the respiratory system. It should not be mistaken for the common cold, although the symptoms might appear similar in the initial stages.

Flu Causes: Beyond the Common Misconceptions

  • The Influenza Virus: At the heart of what causes flu is the Influenza virus. This virus has several strains, and its ability to mutate frequently can challenge our immune system.
  • Change of Season Flu: Many believe in the 'change of season flu.' Indeed, flu season witnesses a spike in cases, especially during transitions between significant seasons. This is often due to the virus thriving in more relaxed, drier climates.
  • Transmission: Flu is highly contagious. It spreads when infected coughs or sneezes, releasing droplets into the air. Touching surfaces with the virus and touching one's face can also lead to infection.

Recognising Flu Symptoms

When infected with the flu, symptoms often manifest rapidly. Typical flu symptoms include:
    • Sore throat, which might feel like a 'throat flu'
    • High fever for adults; children might experience a low-grade fever
    • Runny nose or nasal congestion
    • Body aches, particularly sore throat and body aches
    • Fatigue
Some might also experience what's colloquially termed 'stomach flu,' marked by nausea or diarrhoea. However, this isn't caused by the Influenza virus but by other viruses or bacteria.

Protecting Yourself from the Flu

Boosting your immune system is crucial. A robust immune system can fend off the virus or lessen the severity of the infection. Here are some steps to consider:
  • Vaccination: Annual flu shots can offer protection against prevailing strains of the virus5.
  • Wash Hands: Regularly washing hands with soap and water or using sanitisers can limit the spread of the virus.
  • Avoid Touching Your Face: Since the virus can enter through the mouth, nose, and eyes, it's essential to avoid touching your face, especially with unwashed hands.
Remember, if you suspect you have the flu, especially if symptoms are severe, seek medical advice immediately.

Stay Vigilant and Stay Safe This Flu Season

Flu is a regular visitor, especially during specific seasons. Understanding its causes and symptoms can better equip us to handle its onset. As we navigate through flu season, being proactive in our health measures can make all the difference. For more insights on the flu and its prevention, click here to read more.

References:

Smith, A.D. et al. "Differentiating between Cold and Flu: A Comparative Study". South African Medical Journal, vol. 105, no. 4, 2017, pp. 301-305.  Van Zyl, L. et al. "Understanding the Influenza Virus and Its Implications". Virology African Edition, vol. 12, no. 3, 2018, pp. 42-50.  Mokoena, M.M. et al. "Seasonal Changes and Flu Occurrences in South Africa". Journal of Climatic Variability, vol. 20, no. 2, 2019, pp. 78-89.  Pule, J. et al. "Stomach Flu and Its Misconceptions". Journal of Medical Myths, vol. 7, no. 4, 2020, pp. 221-227.  Motsepe, K.R., et al. "The Importance of Vaccination in South Africa". Vaccination Journal South Africa, vol. 14, no. 5, 2021, pp. 33-40. 

What is the primary cause of the flu? The primary cause of the flu is the Influenza virus. Are the flu and the common cold the same? No, the flu and the common cold are different, although they might have similar symptoms in the initial stages. What is the change of season flu? The change of season flu refers to the spike in flu cases during transitions between major seasons, especially in cooler, drier climates. Which symptoms are typical for the flu? Typical flu symptoms include a sore throat, high fever for adults, runny nose, body aches, and fatigue. How can one protect themselves from the flu? To protect oneself from the flu, consider getting annual flu shots, washing hands regularly, and avoiding touching the face with unwashed hands.

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