What are signs that your immune system is fighting a virus?

Summary: When the immune system is fighting a viral infection, it triggers symptoms like fever, fatigue, coughing, muscle aches, and a runny nose, which are signs of the body’s defence mechanisms at work. These symptoms result from the immune system’s innate and adaptive responses, including the release of immune cells, fever to combat the virus, and inflammation to fight infection. To support the immune system, it's important to maintain a balanced diet, stay hydrated, exercise moderately, get enough sleep, and practice good hygiene. For mild symptoms, rest and hydration help, while severe symptoms may require medical attention.

The immune system plays a vital role in protecting the body from harmful viruses. When a virus enters the body, the immune system diligently works to identify, target, and eliminate it. Understanding the signs that the immune system is actively combating a virus can help people know when they are sick and when medical care is necessary. Let’s explore some common signs that the immune system is fighting a viral infection.  

How the immune system fights viruses

The immune system responds to viruses through innate immunity (immediate reaction) and adaptive immunity (specific defence). 

Innate immunity:

Innate immunity serves as the body’s initial barrier. The skin, mucous, and stomach acid work to prevent viruses from entering. If a virus breaches this barrier, infected cells release warning signals known as interferons to slow down the virus. Certain immune cells, such as Natural Killer (NK) cells, identify and eliminate infected cells, while macrophages and dendritic cells capture the virus and trigger a more robust defence. 

Adaptive immunity:

Adaptive immunity functions as the body’s intelligent response. Killer T cells hunt down and destroy infected cells, while Helper T cells coordinate the attack. B cells produce antibodies that attach to viruses and inhibit their spread. After the body eliminates a virus, memory cells retain information about it, allowing the immune system to respond more swiftly in the future—this is the principle behind vaccines. 

Additional defences:

Additional defences include fever, which hinders virus proliferation, and inflammation, which recruits more immune cells to the site of infection. All these mechanisms collaborate to maintain your health. 

Signs that your body's immune system is fighting the virus

When your immune system is fighting a virus, you might observe various symptoms that indicate an active immune response. Here are a few signs: 

• Fever: The body increases its temperature which can enhance the activity of immune cells and promote a more effective immune response.  
• Fatigue: The immune system consumes a lot of energy to fight the infection, making you feel exhausted and frail. 
• Coughing and sneezing: These are processes to expel the virus from the respiratory system.  
•  Runny or stuffy nose: The body generates extra mucous to remove the virus from the nasal passages.  
•  Swollen lymph nodes: Lymph nodes enlarge as they produce immune cells to defend against the virus. 
• Muscle aches: The inflammation caused by the immune response may result in pain in muscles and joints.  
• Chills: As the body increases its temperature to combat the virus, chills may emerge as a symptom of the fever.  
• Loss of appetite: The immune system instructs the body to prioritise fighting the virus over-consuming food.  

These signs are common when the immune system is actively fighting a viral infection, and while they may be uncomfortable, they signal that your body is working to protect itself.  

Also read: Immune system check: How to tell if your immune system is weak? 

Boosting our natural defence system

Strengthening your body’s natural defence system is vital for preserving general health and increasing your ability to fight infections. Here are some effective ways to enhance your immune system: 

• Eat a balanced diet: A diet rich in fruits, vegetables, lean proteins, and whole grains provides necessary vitamins and minerals, such as vitamin C, vitamin D, zinc, and antioxidants, which support immune function. 
• Stay hydrated: Drinking sufficient water supports the proper functioning of all body systems, including the immune system. Proper hydration also ensures the smooth circulation of nutrients throughout the body.  
• Exercise regularly: Regular, moderate exercise helps ensure good circulation and enhances immune function by promoting healthy blood flow, which allows immune cells to travel more effectively throughout the body. Activities such as swimming, walking, or cycling are ideal. However, excessive intensive exercise may temporarily weaken immunity. 
• Get enough sleep:  Restful sleep is essential for a robust immune system. Sleep supports cell repair and regeneration, and insufficient sleep can weaken immune function.  
• Avoid smoking and limit alcohol: Smoking compromises the immune system, reducing the body’s ability to fight infections. Likewise, excessive alcohol consumption can disrupt the immune system. Cutting down or eliminating these habits helps improve overall immune health.  
• Practice good hygiene: Regular handwashing, using hand sanitisers, and practising good personal hygiene can help prevent infections from entering the body. Reducing contact with pathogens eases the workload on your immune system. 

Also read: Immune System Test: How do I know if my immune system is weak? 

Where to get help

If you're dealing with a viral infection, there are several ways to get the right support: 

• For mild symptoms, rest, stay hydrated, and use over-the-counter medications to relieve fever or pain. 
• For severe symptoms like difficulty breathing, chest pain, or a high fever, seek medical attention immediately. 

For convenient care, telehealth online doctor with Hola Health let you consult with Australian-registered doctors online 24/7, from the comfort of your home. Get medical certificate, instant script, GP referral via telehealth appointments in minutes from registered Australian doctors. 

You can visit a local clinic, hospital, or urgent care facility for in-person assistance. Pharmacies can also provide guidance on symptom management. Public health websites offer trusted information about common viruses like COVID-19 or the flu. If unsure, call a healthcare helpline for advice. Preventive care and vaccinations from healthcare providers can help reduce the risk of viral infections. If symptoms worsen, always seek professional medical help. 

In conclusion, symptoms like coughing, fever, fatigue, and body aches are signs that the immune system is combating a virus. Though unpleasant, these signs indicate that the body is actively protecting itself. Sufficient rest, fluid intake, and proper care are crucial for supporting the immune system’s recovery.