Influenza, more commonly known as the flu, is an infection of the respiratory system caused by influenza viruses. Due to its symptoms—particularly high fever, severe fatigue, and muscle aches—patients often find themselves unable to perform daily activities, which is why it’s sometimes informally referred to as the “rag disease.”
CAUSE OF FLU: INFLUENZA VIRUSES
The flu is caused by two main types of influenza viruses: Type A and Type B. Among these, Type A is known for triggering widespread outbreaks and is capable of infecting not only humans but also animals such as pigs, horses, and birds. Type B, on the other hand, infects only humans and is generally associated with more localized outbreaks. Influenza A also includes subtypes that predominantly affect animals; a well-known variant is avian influenza, or bird flu. Although transmission of such strains to humans has historically been rare, the potential for these viruses to cause pandemics remains a serious concern among health professionals.
SYMPTOMS AND INDICATIONS OF INFLUENZA
After a brief incubation period of one to two days, flu symptoms typically emerge abruptly. These symptoms include high fever (usually ranging between 38°C and 41°C), headaches, extreme fatigue, dry cough, sore throat, nasal discharge, and body aches. The fever often subsides after 3 to 5 days, but feelings of tiredness and general weakness can linger longer. In most healthy individuals, symptoms clear up within a week. However, the flu can lead to severe and even life-threatening complications in people with weakened immune systems, underlying health conditions, the elderly, and young children. One of the most common complications is pneumonia, which may result either from the viral infection itself or as a secondary bacterial infection.
DISTINGUISHING FLU FROM THE COMMON COLD
Although flu and the common cold are both viral illnesses affecting the respiratory system, they differ significantly in terms of symptoms and severity. The cold is caused by a wide range of viruses—over a hundred known types—which explains why individuals can catch colds frequently. The hallmark distinction between the two is the presence of fever in influenza, which is typically absent in a regular cold. Moreover, while cold symptoms are generally mild and allow individuals to continue with daily activities, flu symptoms can be intense enough to confine someone to bed. Despite some overlap—such as nasal congestion, sore throat, and coughing—the overall impact of the flu is far more debilitating.
HOW FLU IS SPREAD
Influenza is highly contagious and is primarily transmitted through airborne droplets released when an infected person coughs or sneezes. These droplets can remain suspended in the air for hours and infect others who inhale them. Flu can also spread indirectly—through surfaces or objects contaminated by the virus. When someone touches a contaminated surface and then touches their face, especially their mouth, nose, or eyes, the virus can enter the body. Physical contact such as handshakes, close conversations (within a meter), and kissing also facilitate the spread of the virus. Crowded settings like schools and offices are particularly high-risk environments for transmission.
MANAGING AND TREATING FLU
Flu treatment does not typically involve antibiotics, as they are ineffective against viral infections. The misuse of antibiotics can lead to bacterial resistance, delaying proper treatment and increasing medical costs. They should only be prescribed if the flu leads to secondary bacterial infections such as sinusitis, pneumonia, or ear infections. Children and teenagers with flu symptoms should avoid aspirin, as it has been associated with Reye’s syndrome—a rare but serious condition. The best approach to flu care includes plenty of rest, hydration, and the use of medications aimed at alleviating symptoms like fever and pain. Antiviral drugs may be prescribed in some cases, but this decision must be made by a healthcare professional. Monitoring for complications is essential, especially in vulnerable individuals.
PREVENTIVE MEASURES AGAINST FLU
Getting vaccinated remains the most effective strategy for preventing influenza. Each year, the World Health Organization reviews the changing nature of influenza viruses and recommends the specific strains that should be included in the vaccine. Recent vaccines generally contain two variants of influenza A and one of influenza B. For instance, this season’s vaccine includes strains like H1N1, H3N2, and a current type of influenza B. When the selected vaccine closely matches the circulating virus, protection levels range from 50% to 80%. In healthy adults, the vaccine often provides over 80% immunity against influenza A. While its effectiveness may be lower in the elderly, it still significantly reduces the severity of illness and related fatalities.
Flu season in the Northern Hemisphere typically peaks during the winter, so it is advised to receive the vaccine in early autumn, preferably in September or October. However, individuals can still benefit from the vaccine if they receive it later in the winter, especially before the second wave of infections in March and April. The vaccine is recommended not only for those at high risk of flu-related complications but also for anyone over six months of age without an egg allergy who wishes to be protected.
Recommended vaccination groups include:
- Adults aged 50 and above
- Residents of nursing homes or chronic care facilities
- Individuals with chronic lung or heart conditions
- Children aged 6 months to 18 years on long-term aspirin therapy
- People suffering from chronic kidney issues
- Individuals with diabetes
- Immunocompromised patients, including those with cancer, HIV/AIDS, or recipients of organ transplants, chemotherapy, or steroids
- Pregnant women
- Healthcare workers including doctors, nurses, and hospital staff