Key takeaways

Colds, often caused by rhinoviruses and coronaviruses, are highly contagious, with individuals potentially spreading the virus for up to two weeks.
The contagious period for a common cold typically lasts from five to seven days after symptom onset but can start one to three days before symptoms appear and last up to two weeks.
Good hygiene practices such as avoiding close contact, practicing hand hygiene, disinfecting surfaces, and wearing masks are recommended to prevent the spread of colds.
While there is no cure for the common cold, symptoms can be alleviated through rest, fluids, over-the-counter medications, and other supportive therapies, though these do not shorten the duration of the cold.

“It’s just a cold.” That’s a sentence many people use to explain why their symptoms are nothing serious, nothing anyone needs to worry about.

The common cold is indeed common. Adults catch an average of two to three of these viral infections annually. Young children can get as many as 10 colds a year. Because colds happen so often, many people continue to work or attend school while feeling just a little bit sick. Or they might take a day off, then return to work or school before symptoms subside. That’s not the healthiest idea.

Colds can lead to complications like sinusitis, bronchitis, and ear infections. They are also easily spread—and the viruses that cause colds remain contagious for longer than most people suspect.

How does a cold spread?

Most commonly, colds are caused by rhinoviruses and coronaviruses. These upper respiratory infections are spread in ways similar to the coronavirus that causes COVID-19—when respiratory droplets from an infected person enter the body of a healthy person.

These respiratory droplets may remain infectious outside the body for several hours and even days, depending on where the droplets land, the amount of virus that lands on a surface, the type of surface it lands on, and other factors such as temperature and humidity. Cold symptoms such as sneezing and coughing propel these virus-laden droplets through the air, into the mouths and noses of others, and onto surfaces. According to the Centers for Disease Control and Prevention (CDC), most colds spread through the air and by touching a surface with viral particles on it, then touching your eyes, mouth, or nose.

How long is a cold contagious?

“The contagious period for a cold usually lasts five to seven days and up to two weeks,” says Neil Schachter, MD, a professor of pulmonary, critical care, and community medicine at Mount Sinai Medical Center and author of The Good Doctor’s Guide To Colds & Flu.

“There are over 200 types of cold viruses, and they can affect a person differently,” explains Dr. Schachter. “So the answer to this question needs to cover a range of time.” Typically, you are contagious one to three days before symptom onset and at least five to seven days after the first signs of sniffles, sneezing, cough, headaches, or sore throat. Then, you can still be infectious up to two weeks after becoming ill.

When is a cold no longer contagious?

The common cold has four stages, with symptoms usually peaking at three days when it is most contagious.

Incubation period: The time between exposure and the onset of symptoms. This stage lasts from 12 hours to three days.
Appearance of symptoms: Common symptoms of sneezing, runny nose, stuffy nose, and a sore throat arrive up to three days after exposure. Cough, headache, exhaustion, and watery eyes are also common signs that your immune system is fighting off a cold virus. A fever is rare. Symptoms usually peak at three days.
Remission: Symptoms should start to lessen after three to 10 days.
Recovery: Symptoms like cough and congestion can linger for two weeks but are less severe than in the first few days. People feel much better, even close to normal.

Even though it’s hard to know exactly how long an individual might be contagious, Dr. Schacter recommends staying home from work or school for at least three days until symptoms begin to lessen.

“Then if you are feeling strong enough, go back to work with a mask and a pump bottle of alcohol-based hand sanitizer,” Dr. Schacter says. “However, if you develop a fever or your cough worsens, stay home and call your doctor.”

How to prevent spreading a cold

Keeping those who have a cold in quarantine is not practical. “The contagious period for a cold usually lasts five to seven days and up to two weeks,” says Dr. Schacter. “Most of us can’t take this much time off, so it’s important to lessen the chance of spreading your cold.”

Since colds are so highly transmissible, following the basics of good hygiene remains the best way to prevent the virus from spreading, says Michael Liu, Pharm.D., associate professor of pharmacy practice at Touro College of Pharmacy.

To prevent colds from spreading:

Avoid close contact with others. No hugging, no handshakes.
Don’t cover a sneeze or cough with your hands. Use a tissue, then dispose of it. Or sneeze into your upper shirt sleeve.
Practice good hand hygiene. That means proper handwashing after coughing, sneezing, or blowing your nose. “Wash hands for 20 seconds with soap and warm water or with an alcohol-based hand rub,” says Dr. Liu. “When possible, avoid touching your eyes, nose and mouth, especially with unwashed hands.”
Disinfect surfaces. This is especially important for high-touch surfaces like doorknobs or elevator buttons.
Wear a mask. Recent reports suggest that wearing a medical-grade mask can prevent cold and flu transmission. Before the onset of COVID-19, Dr. Schacter found it harder to convince patients to wear masks.

“Since this deadly virus appeared, people are more comfortable with wearing masks and carrying around a small bottle of hand sanitizer,” says Dr. Schacter. “As an interesting point, when we all started using these two tools, the number of cases of both colds and flu dropped sharply—a sign of how well they worked to protect against respiratory viruses.” In other words, these steps can also help prevent other infectious diseases that spread this time of year.

How to treat a cold

There is no proven cure for the common cold. However, there are ways to alleviate cold symptoms. First, you get plenty of rest and drink lots of fluids. Then, try other supportive therapies such as chicken soup, zinc and vitamin C supplements, cough drops, humidifiers, sinus rinses, gargling with salt water, or warm tea with honey.

“In addition, there are multiple over-the-counter and behind-the-counter medications available as both single-ingredient or multi-ingredient formulations, and they may be administered by mouth as a tablet, capsule, liquid, or lozenge,” explains Dr. Liu. The formulation you need will vary depending on your symptoms.

Common ingredients in cold medications include:

Decongestants (such as phenylephrine, pseudoephedrine, or oxymetazoline) shrink blood vessels in the nose to relieve sinus pressure and stuffy noses. However, they can raise blood pressure, so discuss these medications with your healthcare provider or pharmacist.
Cough suppressants (such as dextromethorphan) ease the constant feeling of needing to cough.
Expectorants (such as guaifenesin) thin mucus and make it easier to expel from your body.
Pain and fever relievers (such as acetaminophen or ibuprofen) suppress the inflammatory compounds your immune system releases to fight a cold virus. This class of drugs prevents their production to ease body aches and headaches.

“Any of these therapies may be utilized to reduce the severity of the common cold symptom,” says Dr. Liu. However, it’s important to note that cold medicines will often contain a combination of these ingredients, so be sure to read labels carefully. “To prevent any risk for medication errors, it is best to consult with a pharmacist on these therapies, especially when administering any of these medications to children younger than six years old, if you are taking multiple prescription medications, or if you have any existing medical conditions.”

“Unfortunately, none of the aforementioned therapies are known to cure or shorten the length of the common cold compared with not utilizing any of them,” says Dr. Liu. “Nevertheless, by utilizing therapies and precautionary measures, you will be better able to withstand the severity of the common cold, and protect those around you from contracting this common condition.”

Given how likely it is that most people will catch at least one cold in the next year, it might be a smart idea to discuss the best decongestants, cough suppressants, and pain relievers with a pharmacist and, ideally, keep some remedies on hand.