Colds and flu: what’s the difference?

Many of my patients are not sure how to tell the difference between a cold and the flu. Their confusion is understandable since colds and flu share some (but not all) of the same symptoms. Here’s how I describe how to tell if you are infected with a cold virus (rhinovirus, coronavirus, respiratory syncytial virus and others may cause the common cold) or a flu virus (influenza):

Both colds and flu share these symptoms:

• Runny nose
• Sneezing
• Watery eyes

Cold or flu sufferers also frequently describe:

• Headaches
• Body aches
• Dry cough
• Fatigue

But the flu is distinguished by:

• Sudden onset
• Fever
• Chills
• Body aches
• Longer duration of sickness

Influenza is a more dangerous infection than the common cold. Since 2010, CDC estimates that the flu has resulted in 140,000 – 810,000 hospitalizations each year. While most people recover from the flu without any difficulty, you should contact your doctor if your symptoms last longer than 10 days, if you have a high fever (more than 103 degrees Fahrenheit) that lasts for more than 3 days, or if you have difficulty breathing, experience vomiting, or have abdominal pain.

Can I prevent myself from getting a cold or the flu?

While there is no way to guarantee that you won’t catch a cold or flu virus, there are some ways to greatly reduce your risk:

1. Vaccines - Colds are caused by many different families of viruses and we have not yet found a way to vaccinate people against such a diverse group of common cold viruses. However, we’ve developed vaccines against influenza viruses, and every year scientists customize the vaccine to the specific subtypes of flu virus that are likely to be the most common that season. The best way to prevent a case of the flu is to get your yearly flu shot (it’s ideal to get your shot in October or November). Most individuals(over the age of six months)are eligible for a flu shot, with rare exceptions for those who are allergic to eggs, or who have certain medical conditions.
2. Hand washing and hygiene -Cold and flu viruses are spread through contact with body secretions from infected people. Sneeze/cough droplets, mucus, and saliva (containing live viruses) may be invisible to the eye, but can live on hands, countertops, door knobs, glassware and silverware for as long as 48 hours! For this reason, it’s important to wash your hands thoroughly after every possible exposure to viruses (15 seconds of washing with warm, soapy water is best) and clean counter tops and surfaces that may have been exposed to human droplets. Products that contain chlorine (bleach), hydrogen peroxide, detergents or soaps, iodine-based antiseptics, and alcohols are the most effective germ-killers.
3. Avoiding contact and preventing virus spread - While it’s not always possible to avoid contact with those who are sick, if you know you have the flu, you should try to stay away from work or school while you are most infectious. Generally, that means that you should stay home if you have a fever and for at least 24 hours after you’re fever-free. Be sure to cover your mouth with the crook of your arm or with a handkerchief when you cough or sneeze, and wash your hands (or use sanitizing gel) immediately afterwards.

What are the best treatments for colds and flu?

Unfortunately, there is no cure for cold and flu viruses once you’ve been infected. The good news is that there are many over-the-counter (OTC) medications and products that can treat your symptoms. If extra rest, drinking hot fluids, nasal irrigation, and saline gargles and washes are not enough to manage your symptoms, you could benefit from:

• Pain medicines -Pain medicines containing active ingredients such as ibuprofen and acetaminophen can reduce fevers, body, and head aches associated with the flu.
• Cough medicines - Cough suppressants are helpful if your cough is keeping you awake at night, or if your chest and belly are becoming uncomfortably sore from coughing. Dextromethorphan is the most common OTC active ingredient in cough medicines. There are additional cough suppressants (that may include codeine, for example) that are available by prescription only.
• Mucus thinners - Sometimes cold and flu viruses trigger the body to produce a large amount of thick mucus. If you feel that you are having trouble coughing out the mucus because it is too thick, medications with the active ingredient guaifenesin is helpful.
• Decongestants - If your nose is stuffed and making it difficult for you to breathe, decongestants can help to reduce the swelling of membranes in your nose.  When the membranes shrink, the mucus output is reduced and an individual is able to breathe through the nose better. Pseudoephedrine and phenylephrine are the two most common active ingredients in OTC decongestants. There are also nasal decongestant sprays available, and they should not be used for more than 3 days at a time.

You should note that OTC cold and flu remedies often contain combinations of pain medicines, cough medicines, mucus thinners, and decongestants. While this may provide extra convenience (you may only need to take one combination pill instead of multiple different ones for the same effect) it’s really important for you to avoid taking too high a dose of any of the active ingredients. Please look at the Drug Facts label of every medicine before you take it. It’s possible that there’s overlap in the active ingredients of your preferred cold and flu medicines.

Please note that young children under the age of 4 years should not be given certain cold and flu medicines. Please check with your pediatrician before giving any medicine to young children and babies.

How can I best prepare for cold and flu season?

Review your cold and flu checklist:

• Get yourself and your family vaccinated against the flu every October or November (unless there’s a specific reason why you can’t get the vaccine, like egg allergy)
• Know the difference between a cold and flu and when to call your doctor for help
• Identify loved ones who are at special risk for flu infections (because they’re younger than 2 months old, older than 65, pregnant, have a lung disease, or weakened immune system) and have their doctor’s phone number on hand in case they come down with flu symptoms. Call their doctor immediately once the symptoms begin. Anti-viral medications may be appropriate but must be started within 48 hours of symptom onset to be effective.
• If you come down with a cold or the flu, make sure you wash your hands frequently, cover your mouth when you cough or sneeze, and keep common surfaces disinfected.
• If you have a fever, limit your contact with others as much as you can until 24 hours after the fever has gone.
• Keep disinfectant products on hand for your home, office, or workplace
• Familiarize yourself with your OTC medicine options, and be sure to read the Drug Facts label before purchasing or taking any medicine

Test Your Knowledge

Q: Why is it recommended to cough or sneeze into the crook of your arm rather than your hand?

A: Germs can spread through direct contact. If you cough or sneeze on your hand, millions of microscopic viruses are transferred onto your skin. Then when you touch a door knob, counter top, or shake someone’s hand, those viruses can rub off. Because you are unlikely to contact as many surfaces or people with the inside of your elbow (try opening a door with your arm!) the viruses deposited after sneezing or coughing are less likely to be transferred off your body. Coughing and sneezing into your arm is a good way to “keep your germs to yourself.”