Cold vs. Flu: Similarities and Differences

Cold symptoms	Flu symptoms
Runny or stuffy nose	Runny or stuffy nose
A sore throat	A sore throat
Cough	Coughing (usually lasts longer)
Mild chest discomfort (uncommon)	Chest discomfort
Sneezing	Sneezing (rare)
Mild body pain (rare)	Severe body pain
Post-nasal drip	Post-nasal drip (uncommon)
Fatigue (rare)	Fatigue
Mild fever	High fever, often with chills
Headache (rare)	Headache (common)

Colds and flu differ in causes, severity and possible complications.

Various viruses cause this

More than 200 viruses can cause the common coldwith the rhinovirus being the most common. Other viruses that cause the common cold include the coronavirus (the common cold), parainfluenza, human metapneumovirus, and adenovirus.

The influenza virus, mainly types A and B, including strains such as H1N1, causes influenza.

The flu is more serious

One of the most noticeable differences between a cold and the flu is the timing and severity of symptoms. Colds develop gradually and cause mild discomfort, making you feel unwell but not seriously ill. Flu symptoms, on the other hand, usually appear suddenly and are much more intense.

Cold symptoms typically peak on the second or third day and disappear within 5-7 days. The flu lasts 1-2 weeksbut the fatigue can last for several weeks.

The flu has a higher risk of complications

Colds rarely lead to complications, although they can occasionally trigger asthma attacks or cause ear or sinus infections. Although most people recover from the flu without serious problems, it can lead to more dangerous health problems, some of which can be life-threatening.

Flu complications can include:

• Bronchitis– swelling and accumulation of mucus in the airways
• Pneumonia, a lung infection
• Sepsis, a life-threatening reaction to an infection
• Swelling of the brain, heart or muscles

Despite their differences, colds and flu share similarities in who they affect, how the viruses spread, and how the diseases can be prevented.

They mainly influence the same groups

Colds and flu can affect anyone, but certain groups get sick more often or have more difficulty recovering from either illness.

People at higher risk of getting sick or developing more serious illness include:

• Adults 65 years or older
• People who are pregnant
• People with chronic health conditions such as asthma or heart disease
• People with a weakened immune system
• Children under 5 years (and especially children under 2 years)

They spread the same way

Both cold and the flu spreads through respiratory droplets when someone coughs, sneezes or talks. You can also become infected by touching surfaces contaminated with the virus (e.g. telephones, doorknobs, light switches) before touching your mouth, nose or eyes.

Viruses that cause colds and flu tend to survive longer and spread more efficiently in cool, dry conditions. This is why both conditions are more common in the fall and winter, when temperatures drop and humidity is lower.

The prevention strategies are similar

The following tips can help you reduce your chance of getting or spreading the flu or cold:

• Avoid close contact (such as kissing or sharing cups) with others when you are sick
• Avoid crowded places, especially if you belong to a risk group
• Do not touch your eyes, face, nose or mouth with unwashed hands
• Clean and disinfect surfaces you touch frequently
• Cover your mouth and nose when you cough or sneeze
• Stay away from people who are sick
• Stay home if you are sick
• Wash your hands often with soap and water for at least 20 seconds

Healthy lifestyle choices can also help prevent colds and flu. Maintaining a healthy lifestyle means getting enough sleep, drinking plenty of water, eating a balanced diet, avoiding smoking and staying active. These steps can strengthen your lungs and immune system, helping you fight off colds and flu.

Some people also take supplements such as elderberry, vitamin C, vitamin D, or zinc to boost their immunity and help prevent disease.

Although colds and flu have many preventive measures in common, only the flu has a vaccine for treatment and prevention. There is no vaccine against the common cold, because different viruses cause the common cold. A annual flu vaccine can help protect you against the most common flu variants, such as influenza A and B.

Because different viruses cause colds and flu, it is possible to get both. However, a coinfection is rare because viruses such as influenza and rhinovirus compete with each other – with one virus typically growing faster in the body.

You may not realize that you are getting a cold and the flu at the same time, but you will probably feel worse than if you had just one infection.

A cold goes away in about a week, and the flu usually clears up within a few weeks with rest, hydration, home remedies, and over-the-counter (OTC) medications.. You should let your healthcare provider know if you or a loved one experiences a cough that worsens while other symptoms improve, if you have a fever that lasts more than three days, if you become dehydrated, or if your chronic condition worsens.

In more serious cases of flu, your GP may refer you to a specialist, such as a pulmonologist for lung problems or an infectious disease specialist for flu complications.

Go to an urgent care clinic if you or someone you know is experiencing:

• Breathing feels a bit more difficult
• Persistent vomiting or diarrhea that does not improve
• Moderate dehydration (a sign of this may be no urine produced for eight hours)
• Persistent high fever that does not respond to medications greater than 102 degrees Fahrenheit (38.9 degrees Celsius) in children or 103 degrees Fahrenheit (39.4 degrees Celsius) in adults
• Symptoms that worsen after initially improving

Seek emergency care if you or someone you know is experiencing:

• Bluish or gray lips or face
• Chest pain
• Confusion
• Fainting
• Retractions (ribs that pull inward with each breath in young children)
• To attack
• Severe dehydration (dizziness, hallucinations, no urine output)
• Severe weakness
• Shortness of breath
• Temperature above 104 degrees Fahrenheit (40.0 degrees Celsius)

Colds and flu are common respiratory illnesses, but different viruses cause them. Both share symptoms such as runny nose, congestion, cough and sore throat. However, flu symptoms tend to be more sudden and severe, also causing fever and body aches.

Prevention strategies include practicing good hygiene, avoiding sick people and cleaning frequently touched surfaces. Although there is a vaccine against flu, there is no vaccine against the common cold. Knowing the differences between the two diseases can help you manage your symptoms and seek medical attention when necessary.