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A User's Guide to the Common Cold

By Brennen Jensen
From evidence-based remedies to recipes for soup, here’s what you need to know to stay healthy during this cold and flu season.

The common cold is aptly named, as Americans sniffle and sneeze through more than 1 billion of them a year, according to estimates from the National Institutes of Health. That breaks down to two or three colds annually for adults and as many as eight for children.

Colds, falling into the larger group of commonly termed upper respiratory infections, are caused by more than 200 different viruses, with rhinoviruses being the most frequent culprit. (“Rhino” means nose—think rhinoceros.) The virus inflames the membranes in the lining of the nose and throat, and the body reacts by increasing mucus production to flush out contaminants. Viruses are also behind the more serious influenza. Meanwhile, fall allergies can mimic coldlike sneezing and wheezing. So when symptoms hit, how do you know what you have? And what are the best ways to treat those symptoms?

We’ve tapped everyone from infectious disease experts to nurse practitioners to providers specializing in Chinese medicine to help you understand symptoms, weed through myths regarding cold care, and know how best to treat a cold. This guide, meant for otherwise healthy adults, provides tips on how to avoid getting sick and to ease the suffering when, alas, you invariably do.

Cold or Flu or Something Else?

Your nose is stuffed, your throat sore. Feeling tired? Achy? Cold or hot? “It’s really difficult to lay out a critical symptom that is or is not associated with either cold, flu, or allergies,” says Andrew Pekosz, an infectious disease specialist at the Johns Hopkins Bloomberg School of Public Health. “There really are an awful lot of gray areas between them.”

But there are ways you can begin to suss out what you might have based on symptoms. “Fever is one thing that is well associated with the flu, can happen with a cold, but rarely happens with an allergy,” Pekosz says. “Things like body aches or general feelings of exhaustion often happen with flu, can happen with a cold, but rarely happen with an allergy.”

Often it’s a matter of severity and the speed of onset. Colds can tease their arrival with a couple of days of mild sniffles or a tickly throat. With flu, you can feel great in the morning and horrible by evening. Another clue is how active flu is in your area. Regional flu outbreaks are closely monitored and will likely be on the local news. Pekosz also suggests checking out websites such as, which compiles both user-reported data and figures from the Centers for Disease Control to track flu at the ZIP code level. Allergies—which cause coldlike nasal chaos—are seasonal, and weather reports and apps usually include pollen reports.

How Did I Get It?

“Colds and flu are usually spread by people who sneeze or cough and send what we call aerosol particles, or droplets, into the air that other people breathe in,” Pekosz says. Virus droplets can also land on surfaces or be transferred there by an infected person’s hands. One of the more overlooked infection methods is hand-to-face—we scratch our nose or rub our eyes and give the virus a way in.

“How many times you touch your face without knowing is incredible,” Pekosz notes. So wash your hands frequently and thoroughly, and carry hand sanitizers containing at least 60 percent alcohol when you’re away from running water. And keep your mitts from your mug. Or try to.

Do I Need Antibiotics?

For viruses, no. They work only against bacterial infections. “People want antibiotics when they start to get a runny nose or sore throat,” says Kimberly Peairs, a doctor of internal medicine and the clinical director of the Johns Hopkins Health Care & Surgery Center at Green Spring Station. “For the vast majority, antibiotics are not indicated because their infections are viral not bacterial.”

When Should I Call My Doctor?

  • Your symptoms last longer than two weeks.
  • Your symptoms worsen or you develop new symptoms.
  • You have a sore throat or fever higher than 100 degrees for longer than three days.
  • You're experiencing intense chest pain and shortness of breath.

How Hot Is Too Hot?

illustration of a woman sweating

Normal body temperature is 98.6 degrees, but anywhere between 97.5 and 98.9 is OK. Fever is another sign that something is off in your body. A rule of thumb is to contact a health care provider when a child has a fever greater than 100.4. But, says Paul Auwaerter, clinical director of the Johns Hopkins Division of Infectious Diseases, “who is experiencing the fever might be the more pressing question—is it someone who is pregnant, elderly, or a neonatal infant? Fever here can be more concerning than in an otherwise healthy child or adult. And if fever goes beyond five to seven days, it could suggest another problem,” Auwaerter adds.

Is It True That You Can't Catch the Same Cold Twice?

Yes and no. When you get over a cold, your body has developed immunity to that strain. Adults get fewer colds than children because of built-up immunity. But don’t think you’re in the clear. “Viruses mutate, and there are thousands of different viral subtypes floating around,” Peairs says. “They can change just enough so that if you are exposed again, you can get symptoms again.”

Picking a Hand Sanitizer

“If you do not have access to soap and water, the CDC recommends that you use alcohol-based hand sanitizers that contain at least 60 percent alcohol,” says Michael Sanchez, a Johns Hopkins family nurse practitioner. “Nonalcohol-based hand sanitizers do not work as well.”

Go to Work or Go to Bed?

illustration of a woman thinking about going to bed or work when sick

“The thing to consider is how many aches and pains you have,” says Pekosz. “It’s one thing if you have a little bit of sniffles, which probably means to make sure you have tissues and practice good sneezing and coughing hygiene. But if you have fever or body aches and pains, you should probably call it a day. You’re not doing yourself or co-workers any favors.” And if illness does make the rounds at work, before blaming the first colleague who showed up with a cough, consider this: “With cold and the flu, there’s a small portion of the population that can get infected and not have symptoms and then spread the virus to other people,” says Pekosz.

Should I Get the Flu Shot?

Maybe you’ve heard the flu shot is never a perfect match for the strain of flu circulating in a given year. Get it anyway. “Always get the flu shot, as there is very little downside to it,” says Peairs. “When a patient tells me they got the flu from the shot, I tell them that’s impossible because it doesn’t contain the live virus.”

Feed a Cold and Starve a Fever?

Or is it the other way around? In any direction, it’s only half right. “Any time you are sick, you should always find ways to get some form of good food into your system,” says Pekosz. “This is where your grandma’s chicken soup works well as an easy way to get some nutrition into your body and keep your energy up to try to fight off the infection.”

Vitamin C or Echinazea to the Rescue?

Probably not. “They have checkered data behind them,” Auwaerter says, noting a lack of scientific study to support efficacy. “I don’t know anybody who espouses using them based on available evidence.”

What About Zinc?

“There’s some evidence that zinc lozenges help,” Auwaerter says. “If you start within 24 hours of symptoms and take at least 80 milligrams a day in divided doses every one to three hours, these might shorten the duration of the illness. Whether it’s actually interfering with the virus or just reducing local inflammation is unclear. The downside is that lozenges don’t taste great and can alter your sense of taste and smell.” Nausea can be another side effect, so take zinc with food.

How About a Hot Toddy?

illustration of a hot toddy

If you knock back a hot water and whiskey with lemon, honey, or cloves, you may feel better. But is this cocktail helping you get better? “While the alcohol component is probably acting as an analgesic and the heat may be relaxing your upper airways and breaking down congestion, I suspect you can get relief in other ways,” says Peairs. “If you have a cold or are feeling poorly, adding alcohol is not typically the best choice.” Booze can dehydrate you when you need fluids the most. So enjoy a hot beverage, but hold off on the liquor until you can raise a toast to feeling well again.

OK, I Have a Cold. Now What?

Get rest, drink fluids, use over-the-counter meds to control symptoms (see our sidebar), cough and sneeze into tissues, and wash hands often to reduce spreading the virus. Then ride it out.

Don't Sweat It?

Exercise is thought to strengthen the immune system, but should you work out when sick? “For mild viral infections, continuing exercise might be a good thing,” says Peairs. “For more severe infections or flu, you should take it easy and allow your immune system to rein in the virus. Just listen to your body. If you have trouble breathing or a cough is exacerbated, it’s a bad idea to continue.”

To Neti or Not to Neti?

illustration of a woman using a neti pot

“Neti pots work really well in performing nasal irrigation, not only for colds but also for patients with nasal allergies,” says Sanchez. “If you want to mix your own saltwater solution, it’s best and safest to use sterilized or distilled water. There are also commercial products marketed for these purposes.”

Should I Toss My Toothbrush After I Get Sick?

“While bacteria and viruses can be on your toothbrush after a cold, you don’t have to toss it,” says Sanchez. “As you recover, your body produces antibodies that fight against the virus. These antibodies will keep you from getting sick from the same virus. If you’re not convinced, you can simply replace it with a new one.”

Understanding Your Snot

“Mucus color is one of many criteria that may help us decide whether cold symptoms are caused by virus, bacteria, or allergies, but it’s not specific to those causes,” says Johns Hopkins physician Michael Albert. “Yellow or green mucus could indicate a bacterial or viral infection, and mucus that’s clear could indicate allergies or a viral infection. Bloody or green mucus is probably a little more suggestive of a bacterial infection, but we would need to consider other criteria as well.”

Sore Throat Relief

A saltwater gargle with about 1 teaspoon of salt per cup of warm water can help reduce the pain and swelling of a sore throat.

Cold-Proof Your Home and Office

“The safe rule of thumb is that most viruses stay active for 24 hours or less on a hard surface, but in truth most viruses probably last eight hours or less,” says Albert. “It takes a very compulsive person to sterilize every surface, but if you do have someone with the cold or flu at home, focus on things that people touch a lot. Doorknobs, appliance handles, keyboards, and tablets. Cleaners containing a mild bleach solution kill viruses, as does hydrogen peroxide. Probably the easiest thing to do is use disposable household antimicrobial wipes.”

Should I Hook Up a Humidifier?

“Ironically, with the congestion and mucus, you also get drying and irritation of nasal tissues. And colds usually come each year when air is dry,” says Albert. “Humidification soothes nasal passages.”

What About Strep Throat?

Streptococcal pharyngitis is a bacterial infection unrelated to colds. The clinical criteria for diagnosing strep are fever, tender lymph nodes in neck, pus and/or swelling visible on the tonsils, and lack of a cough. “There’s a rapid strep test that can help confirm a diagnosis while you wait,” Albert says, “though it’s not as accurate as a throat culture, which takes one to three days to return.”

Has Your Cold Gone "Rogue"?

Because your body is weakened and congestion creates a favorable environment in the sinuses and ears, you may aquire a bacterial infection. “When a bacterial infection sets in, there’s often a second spike of symptoms seven to 14 days after the start of the cold,” says Albert. “They may be new symptoms—a deepening cough or an earache. For people who develop pneumonia, it could be worsening fever and a painful, much deeper cough.”

Advice from Eastern Medicine

illustration of acupuncture needles and a mortar and pestle

Rachel Waldman is an acupuncturist and herbologist with the Johns Hopkins Integrative Medicine and Digestive Center. When the seasons change, she reminds her patients to eat well and get plenty of rest to prevent illness. If a patient does get sick, acupuncture can help. “Sometimes patients will call to cancel an appointment if they’re not feeling well, but acupuncture is very helpful and supportive to the immune system,” Waldman says. “When you have a virus, there’s not a lot that you can do to treat it except for supportive measures that relieve symptoms and help you sleep. Ultimately, it’s your immune system that fights it off, and anything we can do to support the immune system and your overall well-being can help move that along and get you feeling better faster.”

In Chinese medicine, “we think of food as medicine,” Waldman says, so she also prescribes herbs and food to her patients. “I recommend soups. They are warming and easy to digest—and the right soup, made with clean ingredients, can benefit the sinuses and lungs, improve energy, and regulate digestion.”

Waldman recommends this soup from the cookbook Ancient Wisdom, Modern Kitchen: Recipes from the East for Health, Healing, and Long Life by Yuan Wang, Warren Sheir, and Mika Ono.

Flu Season Soup

illustration of a soup bowl with hot soup and vegetables


¾ cup pearl barley or coix (Job’s tears, yi yi ren in Chinese, or hato mugi in Japanese)
3 ½ cups water
1 tablespoon vegetable oil, such as canola or olive oil
½ medium-size onion, cut into ½-inch pieces
2 cloves garlic, peeled and minced
2 to 3 medium-size stalks celery, cut into ½-inch slices
1 cup cooked azuki beans, kidney beans, or black beans (hei dou), or a 15-ounce can, drained
2 teaspoons dried thyme
1 cup chicken or vegetable broth
1 leek, well-washed, cut into ¼-inch slices, roots and the tough tips discarded
½ cup fresh or frozen green peas
Black or white pepper
A handful of arugula, roughly chopped into 1- to 2-inch pieces (about ¼ cup chopped)


  1. Combine the barley and water in a large pot, bring to a boil, then lower the heat and cook, uncovered, at a gentle simmer for about 30 minutes.
  2. Heat the cooking oil in a large pan over medium heat, then add the onion and garlic. Cook, stirring, until golden brown.
  3. Add the celery, beans, thyme, and broth to the pan. Cook, covered, for 15 minutes. Gently stir the beans against the side of the pan to break them open. (If at any point during this or later steps, the mixture becomes too thick or the ingredients threaten to stick to the bottom of the pan, add water.)
  4. Add the bean mixture to the pot of barley, along with the leeks and peas, and season with pepper.
  5. Simmer for another 15 minutes, until the barley is soft.
  6. Add salt to taste (the amount will vary, depending on the amount of salt in your stock).
  7. Sprinkle the arugula on top of the dish as a garnish.
Illustration of tissues, tea, cough syrup and other related cold remedies
Illustrations by Lucy Cartwright

The Cold Aisle Demystified

Multisymptom, maximum-strength, nighttime, daytime—what should you take? Physician Michael Albert breaks it down:

An expectorant is helpful because it thins your mucus so it drains better from your nose and sinuses and lets you cough it up more easily. This keeps the mucus from sitting there and festering. Mucinex is a popular brand, but the generic version is guaifenesin. I recommend it a lot to people with congestion and cough.

Decongestants reduce the amount of mucus you make and can pair well with an expectorant. The challenge is that most of them can raise your blood pressure and should be used with caution, or not at all, by people with high blood pressure or an underlying cardiac condition. The two principal types are pseudoephedrine—Sudafed— which is now controlled and sold behind the pharmacy counter, and phenylephrine, which is less potent and is still sold on the shelf.

Antihistamines also reduce mucus production and are very helpful with allergies. But even a cold can trigger histamines, a chemical in the body that leads to congestion. Two older antihistamines, chlorpheniramine and diphenhydramine (Benadryl), sedate you so they are the ones often used in nighttime formulations. The newer antihistamines are nondrowsy and include the brands Zyrtec and Claritin.

Cough suppressants reduce the urge to cough. Dextromethorphan is a common
one, and you will see the abbreviation DM on products. It is actually a very mild opioid derivative. Codeine is probably the most effective cough suppressant, but it is prescription only and has to be used with caution, as it is a stronger opioid. Robitussin with codeine is my olive branch to patients who come in with a really nasty cough and think they need antibiotics (when they don’t). It helps them get a good sleep and feel better in the morning.

“In the end, healthy adults can pretty much take anything on the shelf as directed,” Albert concludes. “The worst case is that it will make you drowsy when you didn’t want to be, or it will be expensive and you didn’t really need it. With children, always follow the age limits, and when in doubt, call a pediatrician.”

illustration of medicine and prescription bottles

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