Learn more about how to prevent the flu and boost your immunity

Influenza (flu) is an acute respiratory infection caused by influenza viruses. It spreads rapidly through respiratory droplets and can lead to severe complications such as pneumonia, respiratory failure, and even death, especially in vulnerable groups like the elderly, children, and people with chronic diseases. Boosting immunity and taking proactive preventive measures are the most effective ways to fend off the flu. Below is a comprehensive guide to flu prevention strategies and immunity-enhancing methods, along with a simple self-assessment for flu risk.

⚠️ Early Symptoms & Harms of the Flu

The flu often has an acute onset, with symptoms that are more severe than the common cold. Recognizing early signs can help you seek timely care and avoid spreading the virus:

Typical Early Symptoms (1–4 days after infection)

High fever: Sudden onset of fever, usually 38.5°C or higher, lasting 3–5 days, accompanied by chills and fever spikes.
Respiratory symptoms: Dry cough, sore throat, stuffy or runny nose. The cough may persist for 1–2 weeks.
Systemic symptoms: Severe fatigue, muscle aches, headache, and loss of appetite. These symptoms are often more prominent than respiratory discomfort.
Gastrointestinal symptoms (more common in children): Nausea, vomiting, and diarrhea.

Hidden Dangers of Untreated/Unprevented Flu

For most healthy adults, the flu resolves on its own within 1–2 weeks. However, if left unmanaged (or if prevention fails), it can lead to serious complications:

Respiratory complications: Pneumonia (viral or bacterial), acute respiratory distress syndrome (ARDS), and bronchitis.
Systemic complications: Myocarditis, pericarditis, encephalitis, and sepsis.
Increased risk in vulnerable groups: The elderly (over 65), children under 5, pregnant women, and people with chronic diseases (diabetes, hypertension, asthma) are more likely to develop severe flu and even die from complications.

❌ High-Risk Behaviors That Increase Flu Risk

The flu spreads mainly through respiratory droplets (when an infected person coughs, sneezes, or talks) and contact with contaminated surfaces. The following high-risk behaviors can increase your chance of getting infected:

Ignoring vaccination: Not getting a flu vaccine annually is one of the biggest risk factors, especially for high-risk groups.
Poor hygiene habits: Not washing hands frequently, touching your mouth, nose, or eyes with unwashed hands (a common way viruses enter the body).
Exposure to crowded places: Spending time in poorly ventilated, crowded areas (e.g., public transport, shopping malls, schools) increases the risk of coming into contact with infected people.
Inadequate lifestyle: Lack of sleep, overwork, and unbalanced diet weaken immunity, making you more susceptible to the flu virus.
Delaying isolation when ill: Continuing to work or study when experiencing flu-like symptoms spreads the virus to others and may worsen your own condition.

✅ Flu Prevention Measures & Immunity-Boosting Methods

Preventing the flu requires a combination of proactive protection and enhancing your body’s natural defense. Incorporate these habits into your daily life:

Core Flu Prevention Strategies

Get vaccinated annually: The flu vaccine is the most effective way to prevent the flu. It stimulates the body to produce antibodies against prevalent flu strains. High-risk groups (elderly, children, pregnant women, chronic disease patients) and healthcare workers should prioritize vaccination before the flu season (usually October–November).
Practice good hygiene: Wash your hands thoroughly with soap and water for at least 20 seconds, especially after touching public surfaces, coughing/sneezing, or before eating. If soap and water are unavailable, use an alcohol-based hand sanitizer (at least 60% alcohol). Avoid touching your face with unwashed hands.
Maintain respiratory etiquette: Cover your mouth and nose with a tissue or your elbow (not your hands) when coughing or sneezing. Dispose of used tissues immediately and wash your hands afterward.
Avoid close contact with the ill: Stay away from people who have flu-like symptoms (fever, cough). If you are ill, stay home to rest and isolate yourself until you have been fever-free for at least 24 hours without using fever-reducing medication.
Improve ventilation: Keep windows open regularly to allow fresh air circulation, especially in indoor spaces with many people. Use air purifiers if necessary.

Effective Ways to Boost Immunity

A strong immune system can help your body fight off the flu virus more effectively. Focus on these key areas to enhance immunity:

Balanced and nutritious diet: Eat a variety of foods rich in vitamins (vitamin C from citrus fruits, bell peppers; vitamin D from eggs, fatty fish), minerals (zinc from nuts, lean meat, legumes), and antioxidants (berries, dark leafy greens). Protein is essential for immune cell production—include chicken, fish, tofu, and dairy products in your diet. Limit processed foods, sugary snacks, and excessive salt.
Regular physical activity: Engage in moderate-intensity exercise for 150 minutes per week (e.g., brisk walking, jogging, cycling, swimming). Exercise improves blood circulation, enhances the activity of immune cells, and reduces stress (which weakens immunity). Avoid over-exercising, as it can temporarily suppress immunity.
Adequate sleep: Aim for 7–9 hours of sleep per night (8–10 hours for children, 7–8 hours for the elderly). During sleep, the body produces cytokines (proteins that fight infection and inflammation) and repairs immune cells. Chronic sleep deprivation impairs immune function and increases flu risk.
Manage stress effectively: Long-term stress raises cortisol levels, which suppresses the immune system. Practice stress-relief techniques such as meditation, deep breathing exercises, yoga, or hobbies (e.g., reading, gardening). Spend time with family and friends to reduce mental pressure.
Avoid harmful habits: Limit alcohol consumption (excessive drinking damages immune cells) and quit smoking (smoking irritates the respiratory tract and weakens its defense against viruses).

📝 A Simple Self-Assessment for Flu Risk

Note: This self-assessment is for preliminary risk screening only and cannot replace professional medical diagnosis. It helps you identify potential flu risks based on symptoms and recent behaviors.

Review Your Recent Behaviors

Have you been in crowded, poorly ventilated places (e.g., public transport, concerts, schools) in the past 2 weeks?
Have you had close contact with someone who has flu-like symptoms (fever, cough) in the past 2 weeks?
Have you not received a flu vaccine this season, especially if you are in a high-risk group (elderly, child, pregnant, chronic disease patient)?
Have you had inadequate sleep, overwork, or an unbalanced diet recently?

Check for Physical Symptoms

Do you have a sudden high fever (≥38.5°C) accompanied by chills?
Do you have a dry cough, sore throat, or stuffy/runny nose?
Do you have severe fatigue, muscle aches, or a headache?

Evaluate Your Risk Level

High risk: If you answered “yes” to any of the behavior questions AND have the above symptoms. Seek medical attention immediately and isolate yourself.
Moderate risk: If you have high-risk behaviors but no symptoms. Monitor your health closely for 1–2 weeks, practice strict hygiene, and avoid close contact with others.
Low risk: If you have received the flu vaccine, avoided high-risk behaviors, and have no symptoms. Continue maintaining healthy habits.

Key Reminder for Self-Assessment

If you are in a high-risk group (elderly, child under 5, pregnant, chronic disease patient) and experience any flu-like symptoms, do not delay seeking medical care. Early use of antiviral drugs (prescribed by a doctor) can reduce the severity of the flu and prevent complications. Even if your self-assessment suggests low risk, maintaining preventive habits and getting vaccinated annually are still essential.

The flu is preventable with the right measures, and a strong immune system is your best defense. By getting vaccinated, practicing good hygiene, maintaining a healthy lifestyle to boost immunity, and staying vigilant with self-checks, you can effectively protect yourself and your loved ones from the flu. Prioritize your respiratory health—small, consistent actions today can help you stay healthy during flu season and beyond.