Influenza and the common cold are both viral respiratory illnesses, but they are caused by different viruses and vary in severity. While colds are generally mild and resolve on their own, influenza can cause stronger symptoms and may lead to complications in some cases. Because they share similar symptoms, many people find it difficult to tell them apart. Recognising the key differences helps with early symptom detection, taking precautions, and knowing when medical attention may be needed.
This article explains how influenza and the common cold differ in causes, symptoms, duration, prevention, and treatment.
Causes of Influenza and the Common Cold
Although both illnesses affect the respiratory system, they come from different viruses.
Influenza is caused by influenza viruses, primarily types A and B, which circulate seasonally. These viruses mutate frequently, hence new flu vaccines must be developed each year to match evolving strains. Influenza spreads easily through respiratory droplets from coughing, sneezing, or touching contaminated surfaces.
The common cold is caused by several different viruses, most commonly rhinoviruses. Other viruses, such as coronaviruses and adenoviruses, can also cause colds. Unlike influenza, colds do not typically lead to severe illness and usually clear up within a short period.
Symptoms: How to Tell the Difference
While influenza and colds share some symptoms, they affect the body differently. Influenza often causes more intense symptoms, while colds are milder and easier to manage.
Symptoms of Influenza
- High fever (often above 38°C), appearing suddenly
- Chills and muscle aches, especially in the back and legs
- Severe fatigue that can last for days
- Dry cough, sometimes worsening over time
- Sore throat and headache, though not always present
- Occasional nausea or vomiting, more common in children
Symptoms of the Common Cold
- Starts gradually, often with a sore throat
- Mild or no fever, usually below 38°C
- Runny or stuffy nose, often with sneezing
- Mild cough, typically caused by postnasal drip
- Mild fatigue, but no significant body aches
How Long Do They Last?
Influenza symptoms usually last one to two weeks. Fever and body aches tend to subside within a few days, but fatigue and coughing may linger, particularly in individuals with lower immunity.
The common cold follows a shorter course, with symptoms peaking around the third or fourth day before improving. Most colds resolve within five to ten days, though a lingering cough or mild congestion may last slightly longer.
Recovery time varies based on individual health. People with existing conditions, young children, and older adults may take longer to fully recover.
Complications: Why Influenza Is More Severe
Colds typically clear up without any lasting effects, but influenza can lead to further health issues, particularly in individuals with existing conditions.
Influenza may lead to pneumonia, bronchitis, sinus infections, or worsening of chronic conditions such as asthma or heart disease. Some individuals, particularly older adults, young children, and those with underlying health concerns, may require hospitalisation.
Colds rarely cause complications but, in some cases, may lead to sinus infections or mild ear infections, which usually clear on their own.
Treatment: Managing Symptoms
Although there is no cure for influenza or the common cold, symptoms can be relieved with rest, adequate hydration, and medications that help reduce discomfort. Managing symptoms early can support recovery and prevent further strain on the body.
Managing Influenza
- Getting plenty of rest allows the immune system to fight the virus, while limiting physical activity helps conserve energy for recovery.
- Drinking fluids prevents dehydration, especially if there is fever or sweating. Warm drinks such as broth or herbal tea can also help soothe the throat.
- Taking fever-reducing medications such as paracetamol can help ease fever and muscle aches. These medications do not shorten the illness but can improve comfort.
- Antiviral medications may be prescribed in high-risk cases but are most effective when taken within 48 hours of symptom onset. They can help reduce the severity and duration of symptoms.
- Eating light, nutritious meals may help maintain energy levels and support immune function. Loss of appetite is common, but small, frequent meals can be beneficial.
Managing the Common Cold
- Staying hydrated helps loosen mucus and ease congestion. Warm fluids such as honey and lemon water may provide relief for a sore throat. Chicken soup is particularly good for that purpose.
- Using saline nasal sprays or steam inhalation can relieve nasal blockages and make breathing easier.
- Taking over-the-counter medications such as antihistamines or decongestants may help reduce discomfort. However, they do not speed up recovery and should be used as needed.
- Gargling with salt water may help soothe a sore throat and reduce irritation. Getting enough rest allows the body to focus on fighting the virus. Avoiding exposure to cold air and irritants such as smoke may help prevent further irritation of the throat and airways.
Prevention: Reducing the Risk of Infection
Influenza and the common cold spread through respiratory droplets released when an infected person coughs, sneezes, or talks. The viruses can also spread by touching contaminated surfaces and then touching the eyes, nose, or mouth. Practicing good hygiene and getting vaccinated can help lower the risk of infection and limit the spread of these illnesses.
Preventing Influenza
- Annual influenza vaccination reduces the risk of infection and lowers the likelihood of severe illness and complications It is worth noting that the influenza vaccine is released twice a year – Southern Hemisphere and Northern hemisphere. Each new release of the vaccine protects individuals from the latest circulating Influenza A and B strains, based on surveillance data from the W.H.O..
- Frequent handwashing with soap and water removes viruses before they can spread. If soap and water are unavailable, using an alcohol-based hand sanitiser can be helpful.
- Avoiding close contact with infected individuals minimises exposure, especially in crowded or enclosed spaces.
- Wearing a mask in high-risk settings may reduce the spread of respiratory droplets, particularly during flu season.
- Maintaining a balanced diet, regular exercise, and adequate sleep may help the body respond to infections more effectively.
Preventing the Common Cold
- Regular handwashing is one of the most effective ways to prevent the spread of cold-causing viruses.
- Avoiding touching the face, especially the eyes, nose, and mouth, reduces the chance of infection.
- Disinfecting frequently touched surfaces, such as doorknobs, phones, and keyboards, helps prevent virus transmission.
- Keeping nasal passages hydrated with saline rinses or humidifiers may help maintain mucosal defences against viruses.
- Maintaining physical distance from people with symptoms lowers the chance of exposure to cold viruses.
When to Seek Medical Attention
Influenza can sometimes lead to complications requiring medical care. Seek medical attention if you experience breathing difficulties, chest discomfort, or a fever above 40°C that does not improve. Severe dehydration, marked by dry mouth, dizziness, or reduced urination, may also require evaluation. If symptoms worsen after initial improvement, a secondary infection like pneumonia could be developing. The common cold rarely requires medical attention, but prolonged congestion or ear pain may indicate a secondary infection that needs evaluation.
Conclusion
Influenza and the common cold share similar symptoms, but influenza tends to be more intense and can last longer. While most cases of both illnesses resolve on their own, influenza may lead to complications, particularly in individuals with underlying health conditions. Taking preventive measures, such as vaccination, good hygiene practices, and maintaining overall health, can help reduce the risk of infection. Recognising the differences between influenza and the common cold allows for better symptom management and ensures appropriate medical care when needed.
If you are experiencing flu symptoms or have questions about vaccination, book an appointment today for professional guidance on prevention and treatment.
