Differences Between Colds and Flu: Symptoms, Causes, and Treatments

Understanding the Differences Between a Cold and the Flu

Both the common cold and the flu are respiratory illnesses that affect millions of people each year. While they share some similar symptoms, colds and flu are caused by different viruses and can have different levels of severity. Understanding the key differences between a cold and the flu can help you distinguish one illness from the other and know how best to treat your symptoms.

Common Cold Symptoms

Colds are caused by over 200 different viruses, with rhinoviruses being the most common culprit. Cold symptoms usually come on gradually and are generally milder than flu symptoms. Common symptoms of a cold include:

• Runny or stuffy nose
• Sneezing
• Sore throat
• Coughing
• Congestion
• Slight body aches
• Mild fatigue
• Watery eyes
• Possible mild fever

Cold symptoms can last anywhere from a few days to up to 2 weeks. While colds are annoying, they typically resolve without medical treatment. Over-the-counter medications can help relieve congestion, body aches, and sore throat pain associated with a cold.

Flu Symptoms

Influenza (flu) is caused by influenza A and B viruses. Flu comes on more rapidly than a cold, and symptoms are typically more severe. Common flu symptoms include:

• Fever and chills
• Body and muscle aches
• Fatigue
• Headache
• Chest discomfort when coughing
• Dry, persistent cough
• Sore throat
• Runny or stuffy nose

Flu symptoms usually last about 1-2 weeks but severe cases can last longer. Flu puts you at greater risk for developing serious complications like pneumonia, bronchitis, sinus infections, and ear infections. People with certain medical conditions, pregnant women, young children and the elderly are at greater risk for flu complications.

Causes of a Cold vs the Flu

The common cold is caused by a variety of viruses, including:

• Rhinoviruses
• Coronaviruses
• Respiratory syncytial virus (RSV)
• Parainfluenza viruses
• Human metapneumovirus

These cold viruses are contagious and spread through contact with infected nasal secretions or objects touched by someone with a cold. Because there are so many different cold viruses, you can get many colds in a row.

Influenza is caused by influenza A, B and C viruses. Influenza spreads through respiratory droplets from coughing and sneezing. Flu outbreaks happen annually, usually in the fall and winter months. Getting an annual flu vaccine offers the best protection against getting the flu.

Diagnosing a Cold vs the Flu

Colds and flu share enough overlapping symptoms that it can be difficult to tell them apart based on symptoms alone. In general, flu symptoms come on faster and more severely than cold symptoms.

To help distinguish a cold from the flu, doctors consider factors like:

• Time of year - colds happen year-round but flu is most common in fall/winter
• Symptom severity
• Symptom duration - flu lasts longer than a cold
• Presence of a fever - more common with flu
• Body and muscle aches - more severe with flu
• Extreme fatigue - more common with flu

If there is uncertainty between a cold or flu, a rapid flu test can be done in your doctor's office to test for the presence of influenza viruses. However, since colds and flu share symptoms, it's possible to test negative for flu but still have a cold.

Treating a Cold vs the Flu

While there is no cure for the common cold, you can find relief from symptoms while your cold runs its course. Some helpful tips include:

• Get plenty of rest
• Stay hydrated
• Use a humidifier for congestion and coughs
• Take OTC medications like acetaminophen (Tylenol) and ibuprofen (Advil) for aches, pains, and fever
• Take decongestants, antihistamines, cough medicine, and throat lozenges
• Avoid smoking and secondhand smoke which can aggravate cold symptoms

For the flu, prescription antiviral medications like Tamiflu may be prescribed within the first 1-2 days of symptoms before it's too late to be effective. Flu antivirals can reduce symptom severity and duration. Other flu treatments include:

• OTC fever/pain reducers like acetaminophen and ibuprofen
• Plenty of rest and fluids
• Avoiding contact with others to prevent the spread of flu
• Treating fever aggressively since fevers over 104 F (40 C) can be dangerous
• Treating any secondary bacterial infections that can happen with flu

Most healthy people recover from flu in 1-2 weeks with supportive self-care and rest. However, the flu can result in serious complications for high-risk groups, so see a doctor immediately if your flu symptoms don't improve.

Preventing Colds and the Flu

While neither colds nor flu can be completely prevented, you can take measures to reduce your risk:

• Get vaccinated - Get an annual flu vaccine each fall. Flu viruses change yearly so annual vaccination against the current strains is needed for the best protection.
• Wash hands frequently - Wash often with soap and water, especially after coughing/sneezing and before eating. Use alcohol-based hand sanitizers when soap isn't available.
• Don't touch your face - Avoid touching your eyes, nose, and mouth since that's how cold/flu viruses enter your body.
• Disinfect surfaces - Clean frequently touched objects and surfaces using disinfecting sprays or wipes.
• Avoid sick people - Stay away from obviously sick people and stay home when you feel ill.
• Improve immunity - Eat a balanced diet, exercise regularly, control stress, and get enough sleep.
• Use masks - Wear a face mask in crowded public settings to reduce viral exposure.

Knowing When To See A Doctor

Most colds and cases of flu can be managed at home with rest and supportive care. But contact your doctor if you experience:

• Difficulty breathing or shortness of breath
• Chest pain or pressure
• Confusion or sudden dizziness
• High fever that lasts more than 3 days
• Flu symptoms that improve but then return with fever and worse cough
• Worsening of chronic medical conditions like heart disease or diabetes
• Severe sinus pain or thick nasal discharge

Seeking prompt medical care if you have signs of complications or if you are at high-risk for flu complications (young children, 65+, pregnancy, chronic conditions) can help prevent serious outcomes. With appropriate rest and treatment, most otherwise healthy people recover fully from colds and cases of seasonal flu.

The Bottom Line

Colds and flu share some common symptoms but are caused by different viruses. Flu symptoms tend to be more severe than cold symptoms. While neither can be cured, rest and supportive care along with flu antivirals in some cases can help you recover. Getting an annual flu shot, washing hands frequently, disinfecting surfaces, and avoiding contact with sick individuals are some of the best ways to reduce your risk of getting sick.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.