Overview of a common cold
The common cold is an upper respiratory infection (URI) that strikes nearly everyone, from older adults to young children. Colds are due to a viral infection of the nose, nasal passages, throat, and windpipe. There is no single “cold virus.” The infection can be caused by any number of different viruses, but the symptoms and duration are largely the same no matter what virus is to blame. Runny nose, stuffy nose, scratchy throat, coughing, low fever, and minor body aches are all common symptoms. These common symptoms last for a few days and then gradually fade away. After about a week of symptoms, people feel normal again. Colds are typically not something to worry about. Taking it easy is about all people need to do, though cold medicines might partly alleviate symptoms. However, in rare cases, a cold might lead to a more serious infection. That’s when a doctor might be needed.
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What causes a cold?
A cold is a viral infection of the upper respiratory tract: the nose, nasal passages, throat, and larynx. Many different viruses can cause a cold. These include:
Rhinovirus (40% to 50% of colds are caused by rhinoviruses)
Influenza (25% to 30%)
Coronavirus (10% to 15%)
Adenovirus (5% to 10%)
Parainfluenza (5%)
Respiratory syncytial virus (RSV) (5%)
Metapneumovirus (5%)
Enteroviruses (small intestine viruses)
Bocavirus
Causes of a cold do not include bacterial infections, lifestyle habits, or environmental triggers such as secondhand smoke.
Risk factors for a cold
There is no general agreement on risk factors for catching colds. Most people catch a cold virus from germ contact with their hands. They first come into contact with a contaminated surface such as another person’s hand, a chair, a TV remote, or money. They then infect themselves when they touch their mouth or nose with their fingers or hands. Hand washing and hand sanitizer use are the most effective ways to avoid catching colds and other upper respiratory tract infections.
Possible risk factors for catching a cold include:
Possible risk factors that could make cold symptoms more severe include:
There is no evidence that people with a weakened immune system are more likely to get cold infections.
Is a cold serious? When to see a doctor
The common cold is usually not a cause for concern. Common cold symptoms may be unpleasant, but they are not health-threatening. Cold infections generally resolve on their own without treatment within a few days.
However, the infection could spread to other parts of the body. Sinus infection, ear infection, strep throat, bronchitis, croup, and pneumonia are possible but rare complications of a cold infection. All these medical conditions will require diagnosis and treatment. Some, like pneumonia, may evolve into life-threatening illnesses.
See a doctor if there’s any suspicion that the problem may be worse than the common cold. Look for symptoms like:
If an infection causes serious problems with breathing, go to an emergency room. Symptoms to watch out for include:
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How is a cold diagnosed?
A healthcare professional will diagnose a cold based on the symptoms. If the healthcare provider suspects that there’s a more serious problem going on, medical tests such as a chest X-ray or blood tests may be needed.
Is a cold contagious?
Colds are highly contagious. The virus spreads through surfaces like tables, chairs, remote controls, doorknobs, and money—anything that people touch. The more an object is handled by different people, the more likely it is to be covered with a cold virus. These viruses can live outside the body for several hours or even several days.
When colds are spreading around, it’s likely to encounter several objects that are contaminated when going about the day’s business. Once the hand is covered with a cold virus, people can infect themselves by touching their face, nose, lips, or mouth with their hands. In this way, they transmit the virus from contaminated objects to tissues inside the mouth or nose.
Healthcare professionals generally don’t believe that colds are spread by breathing aerosols, such as the water droplets that get blown into the air when people shout, cough, or sneeze.
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Is a cold curable?
The common cold is not curable but goes away in seven to ten days. Some people may have symptoms for up to three weeks, but that’s uncommon. While a cold is raging, it may feel bad, but is not health-threatening. It won’t put people in a hospital unless it precipitates another infection somewhere else in the body.
The most common treatment for the common cold is to get plenty of rest and drink plenty of fluids.
Common cold symptoms can be managed with over-the-counter cold medicines. Symptom medications include:
Over-the-counter pain relievers such as ibuprofen or acetaminophen for body aches
Over-the-counter antitussives for coughing
Over-the-counter decongestants or nasal sprays for nasal congestion
Over-the-counter antihistamines for watery eyes and sneezing
Expectorants to loosen mucus
Zinc supplements to reduce the duration and severity of a cold
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How to prevent a cold
People have a bewildering variety of ways to try to prevent colds. Unfortunately, most are ineffective at preventing colds. What does medical science say? The research shows that the best ways to prevent colds are:
Hand-washing
Use of hand sanitizer
Gloves
Masking
Gloves and masking may be impractical for many people, but good hand hygiene can prevent not only colds but other infections such as CoVid-19. For all practical purposes, handwashing and hand sanitizer are fundamental to preserving health.
According to the Canadian Medical Association Journal, some ways that probably help prevent colds are:
Zinc supplements
Probiotics
Gargling with salt water
Some common methods of preventing colds may or may not work. The evidence is mixed or indicates there’s almost no benefit. These include:
Ginseng
Garlic supplements
Exercise
Vitamin C
Vitamin D
Echinacea
However, many of these cold preventatives are good for a person’s health like probiotics, exercise, vitamin C, and vitamin D. Whether they prevent colds or not, they’re still good as long as they’re not taken to extremes.
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FAQs about cold causes
What virus causes the common cold?
Colds are caused by many different viruses. The most common are rhinoviruses.
What causes a summer cold?
Summer colds are caused by the same viruses that cause them at any other time of year. Summer colds are not common, though. That’s why people think they’re unusual. Cold viruses are caught by handling contaminated surfaces like doorknobs or coins and then wiping the virus on one’s mouth or nose. The viruses that cause colds can only live a few hours or days out in the open. Then they die. Colds and other viruses survive longer in the cold. They perish more quickly in the summer heat. That’s why winter and spring are cold seasons and summer is not.
Can you catch a cold from being cold and wet?
A common misconception is that being cold or wet makes people more vulnerable to getting a cold or other viral infections. In actuality, you get colds by handling surfaces that are covered in cold viruses. Those viruses live longer out in the open when it’s cold, so people get more colds when it’s cold. People also get cold when it’s cold. That’s the connection.
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