What is a cold?
A cold is a contagious upper respiratory infection that affects your nose, throat, sinuses and trachea (windpipe). More than 200 different viruses can cause a cold, but most colds are caused by a rhinovirus.
How common are colds?
As its name implies, the common cold is widespread. You’ll probably have more colds in your lifetime than any other illness. Adults catch two to three colds a year, while young children come down with a cold four or more times a year.
Are colds contagious?
Colds spread from person to person. For you to become infected, the virus has to get to one of your mucous membranes — the moist lining of the nostrils, eyes or mouth. That happens when you touch a surface or breathe moist air that contains the cold virus.
For example, when a sick person sneezes or coughs, droplets of fluid containing the cold virus are launched into the air. If you breathe in those droplets, the cold virus takes root in your nose. You can also leave virus particles on surfaces you touch when you’re sick. If someone else touches those surfaces and then touches their nostrils, eyes or mouth, the virus can get in.
Why do colds occur in the winter?
You can catch a cold any time of year, but it’s more likely during colder months. In winter, people stay indoors and are in closer contact with each other.
A recent study in mice suggests cold temperatures may also affect your immune system’s response. Researchers found that when cooler air lowered nose temperature, mouse immune systems had a harder time stopping the rhinovirus from multiplying. The same may be true in humans.
Why do children get more colds?
Because young children haven’t been exposed to viruses before, they get more colds than adults. Their immune systems have to learn how to recognize and deal with these new germs. By the time you become an adult, you’ve had many colds. It’s easier for your immune system to identify and attack similar viruses.
Children are also in close contact with other children. Kids typically don’t cover their coughs and sneezes or wash their hands before touching their faces — steps that prevent the virus from spreading.
Symptoms and Causes
What causes the common cold?
Rhinoviruses cause up to 50% of common colds. There are more than 100 different rhinoviruses. But other types of viruses can also cause cold symptoms.
What are the symptoms of a cold?
Within one to three days of picking up a cold virus, you’ll get symptoms like:
- Runny nose.
- Sore throat.
- Nasal congestion.
- Fever (most common in children).
How can you tell the difference between a cold and flu?
It can be hard to tell whether you have a cold or flu, since many of the symptoms are the same. Both are widespread during the colder months and affect the upper respiratory system (nose, throat and trachea). But different viruses cause cold and flu. The flu comes from the influenza virus, while many other types of viruses cause colds.
The main difference between cold and flu is that you’re more likely to have a fever and chills with flu. Adults don’t usually get a fever with a common cold, although kids sometimes do.
The flu also causes body aches and more severe symptoms than a cold. Although both the cold and flu can lead to complications, flu complications can be life-threatening.
What’s the difference between a cold and COVID-19 (the novel coronavirus)?
You might have heard that the common cold is a coronavirus. Coronaviruses are a group of viruses that can cause upper respiratory infections. While rhinoviruses cause most types of common cold, a few are caused by different coronaviruses. Most people recover quickly from these common colds.
Coronaviruses may also travel into the lungs and lead to pneumonia and other complications that can be fatal. A new (novel) type of coronavirus, discovered in late 2019, causes a specific disease known as COVID-19. Early symptoms that make COVID-19 different from the common cold include:
- Chills and shaking.
- Shortness of breath.
- Loss of taste or smell (anosmia).
What’s the difference between the common cold and a chest cold?
A chest cold, or acute (short-term) bronchitis, causes irritation and a buildup of mucus (snot) in the lungs. Common colds turn into chest colds when the virus travels from the nose and throat to the lungs. Occasionally, bacteria cause chest colds.
You can have a cough with a common cold or a chest cold. But chest colds produce a wet cough, meaning you may feel or cough up phlegm. You may also have:
- A cough that keeps you up all night.
- Shortness of breath.
- A sore chest.
Does having a cold affect pregnancy?
Having a cold during pregnancy isn’t usually dangerous. But you do need to be careful with what cold medications you take to treat symptoms. Your healthcare provider can let you know which ones are safe to use during pregnancy.
If you think you may have flu, or if you develop a fever, you should contact your healthcare provider right away. You may need immediate treatment. Fever during early pregnancy is associated with birth defects.
Diagnosis and Tests
How is a cold diagnosed?
Typically, an exam is enough to determine if you have a cold. During a physical exam, your healthcare provider will check for signs such as:
- Swelling in the nostrils.
- Stuffy nose.
- Red, irritated throat.
- Swollen lymph nodes (lumps) in the neck.
- Clear lungs.
You may need tests if your provider suspects you have the flu or another condition. Your provider may give you a nasal swab test (cotton swab rubbed inside your nose) to test for the flu virus. Chest X-rays rule out bronchitis or pneumonia.
Management and Treatment
How are colds treated?
There’s no cure for a cold. You have to let it run its course. Over-the-counter medications can reduce your symptoms to keep you more comfortable until you recover.
Why can’t antibiotics cure a cold?
Antibiotics are medications that fight infections caused by bacteria. Because viruses cause colds, antibiotics don’t work for colds.
What cold medicines relieve symptoms?
Over-the-counter medications to treat cold symptoms are widely available. But some of these medications aren’t safe for children. Check with your healthcare provider before giving your child over-the-counter medications. Be careful not to combine medicines that treat multiple symptoms. If you do, you could wind up overdosing (getting too much) of some ingredients, which could cause other health problems, including organ damage.
Medications that relieve cold symptoms include:
- Pain relievers: Acetaminophen (Tylenol®) and NSAIDs such as ibuprofen (Advil®) relieve headaches and fever.
- Decongestants: Drugs like pseudoephedrine (Contac Cold 12 Hour® and Sudafed®) and phenylephrine (Sudafed PE®) are intended to reduce stuffiness.
- Antihistamines: Diphenhydramine (Benadryl®) and other antihistamines stop sneezing and a runny nose.
- Cough suppressants: Medications such as dextromethorphan (Robitussin® and Vicks DayQuil Cough®) and codeine reduce coughing.
- Expectorants: Guaifenesin (Mucinex®) and other expectorants thin and loosen mucus.
What are the best cold remedies?
Researchers haven’t found that any of those remedies can prevent colds. But zinc may shorten the illness and reduce symptoms. However, it may cause permanent loss of smell, especially when you use it in nasal sprays.
The best and safest way to make a speedy recovery is to get plenty of rest. Consider taking time off from work or school for at least the first few days of illness. Not only will you have more time to rest, but you’ll avoid spreading germs to others.
Also, make sure you’re drinking plenty of fluids to keep your nose and throat moist. Avoid alcohol and caffeine because they have a drying effect.
How can you keep from getting a cold?
There are several steps you can take to prevent a cold including:
- Wash your hands, especially before eating or preparing food. You also want to wash your hands after using the bathroom, wiping your nose or coming in contact with someone who has a cold.
- Avoid touching your face. Cold viruses spread from your hands to your eyes, nose and mouth.
- Clean frequently used surfaces. Viruses can live on doorknobs and other places people often touch.
- Use hand sanitizers when you can’t wash your hands with soap and water.
- Strengthen your immune system so your body is ready to fight off germs. Get enough sleep, eat a healthy diet and exercise.
- Stay home while sick to make sure you don’t spread the cold to others.
Outlook / Prognosis
How long does a cold last?
Colds generally go away within seven to 10 days.
When can you return to work or school?
You can be contagious for up to two weeks, even spreading a cold a day or two before you have symptoms. But you’re most contagious when your symptoms are at their worst – usually the first three days you feel sick.
Can a cold kill you?
The common cold isn’t fatal. In some people, especially those with a weakened immune system, a cold could lead to other conditions that could cause severe health problems. Those complications might include:
When does a cold require a doctor's care?
Contact your healthcare provider if you have any of the following:
- High fever.
- Chest pain.
- Ear pain.
- Asthma flare-up.
- Symptoms lasting longer than 10 days or getting worse.
Seek medical care if your child:
- Develops a high fever.
- Stops eating.
- Cries more than usual.
- Has ear or stomach pain.
- Starts wheezing.
- Is sleepier than usual.
Although they cause discomfort, colds are usually harmless. You can manage the symptoms with medications. Speed up your recovery by getting plenty of rest and fluids, and avoid being around others. If you don’t feel better in 10 days, see your healthcare provider.