Many people confuse the flu and cold, but they are very different viruses with very different risks, preventative options, and treatment strategies. What should everyone know about influenza, the cold, and the difference between the two?

How many times have you said you have a "cold" or "flu" based on a quick judgment of the symptoms you're experiencing — without ever really knowing which virus your body is currently trying to fight off? Because the common cold and influenza are both viral respiratory infections that share some common symptoms, it can be hard to tell them apart — and that's why we're covering this duo together.

Influenza and the common cold are, however, nowhere near the same thing. While they'll both make you feel rather unpleasant for a while, they have different causes, can be prevented in different ways, come with different treatment options and actually do have significantly different symptoms as well. What's more, the flu is much more serious than a cold. 

What should every person who cares about their health know about the flu, common colds, and the differences between the two?

What is influenza, and what is a common cold?

Influenza, also called the flu, is a respiratory infection caused by members of the influenza virus family. These include the influenza A and B viruses that are responsible for causing the majority of seasonal flu cases, as well as less common ones — influenza C and D. You'll have seen that different strains of the flu are given different names, such as H1N1, which don't seem to correspond to any of the names of the different types of flu viruses. This is because the names flu strains are given are derived from the protein found on the surface of each strain. 

Between three and 11 percent of the US population is affected by seasonal flu viruses each year, and though many people will feel terrible for two weeks or so and then recover completely, the flu can be a serious condition that requires hospitalization and even becomes life-threatening in some cases. 

"The common cold", on the other hand, is an umbrella term for infections of the throat and nose that can be caused by over 200 unique viruses — most often rhinoviruses, which account for up to four in 10 cases, but also, among many others, coronaviruses and respiratory syncytial virus. Over a billion common colds run their course in the US alone each year, and colds are also the most common reason for people to visit their doctor. Colds aren't usually serious and most people recover within a week. As with the flu, however, complications are indeed possible in vulnerable people, though this is rarer with the common cold. 

Flu vs common cold: What are the differences in symptoms?

The symptoms of a common cold will generally unfold gradually over a period of days:

  • A runny or congested nose are both common symptoms of a cold. 
  • Sneezing is a very normal part of having a common cold.
  • A sore throat is another typical symptom. 
  • You may experience some discomfort in your chest along with a cough, but it won't be that bad. 
  • People experiencing a cold may feel slightly achy all over, but these aches will be fairly mild. 
  • Some people will feel fatigued and weak when they are fighting off a cold. They're still unlikely to need to spend all day in bed.
  • Some people who have a cold will run a slight fever, but this is uncommon. 
  • Chills are, again, possible but not common. 
  • It is rare, meanwhile, to experience a headache while you have a common cold. 

Flu symptoms, on the other hand, are different:

  • Symptoms come on suddenly. 
  • Most — but not all — people with influenza will experience a fever. 
  • If you have the flu, you're extremely likely to experience all-over body aches that are quite severe. 
  • Chills are common. 
  • The flu is very often marked by an all-encompassing feeling of fatigue. 
  • Headaches are another typical part of the flu. 
  • On the other hand, while a cough and chest discomfort are typical, sneezing and a stuffed or runny nose are much less so. 

Complications of the flu

The Centers for Disease Protection (CDC) estimates that 48.8 million in the United States fell victim to influenza during the 2017/2018 flu season. A total of 959,000 people needed to be hospitalized, and 79,400 ultimately died from flu-related causes. This, in short, sums up why it's important to be aware of the possible symptoms of the flu, as well as the steps you can take to prevent and treat the flu. 

Complications that can result from influenza include:

  • Myocardititis — inflammation of the heart
  • Encephalitis — inflammation of the brain
  • Guillain‐Barre syndrome — a neurological autoimmune disease that can strike as people recover from a viral infection
  • Rhabdomyolysis — a serious condition that can cause muscle weakness, seizures, and even kidney failure
  • Sepsis
  • Pneumonia
  • Ultimately, of course, death

While even healthy, active, adults can experience flu complications, groups who are more vulnerable to include:

  • The very young, those over 65, and pregnant women. 
  • People with chronic health conditions including asthma, COPD, heart disease, diabetes, cancer, HIV, kidney disorders, liver disorders, and more. 
  • Native Americans and Alaska Natives. 
  • People who live in long-term care facilities, regardless of age — as the flu spreads more easily here. 

Preventative steps: How can you protect yourself against the flu?

The flu is highly contagious. It is possible to pick the virus up by touching a surface contaminated with it and then rubbing your mouth, nose, or eyes. This is why steps like washing your hands frequently and properly (with soap and water for at least 20 seconds), not touching your face with unwashed hands, and wiping surfaces down with disinfecting wipes are steps that help minimize your risk. 

The flu is airborne, too, however. You can get it just by being within six feet of an infected person — who will spread the viruses by talking, coughing, sneezing, or just breathing. This is why staying away from sick people, minimizing time spent in crowded public places during flu season, and even wearing a surgical mask help as well. You can personally help protect more vulnerable people against the flu by not going out (except to visit the doctor) when you think you have the flu, covering your mouth and nose when you sneeze or cough, and, again, washing your hands often so you do not spread your germs around. 

While all these preventative steps have an important role to play in the prevention of infectious illnesses, we also have a far more potent weapon available in the fight against influenza. This is, of course, the annual flu vaccine. Getting a flu shot doesn't guarantee that you won't catch influenza, but it does greatly reduce the odds. Should you still get the flu, your symptoms will also be milder and the duration of your illness will be shortened. 

So, who should get a flu shot? The CDC actually strongly advises that everyone over the age of six months should receive a flu vaccine, by the end of October to ensure maximum protection. Some immunocompromised people are the exception. In the case of people who cannot be vaccinated, the rest of us can help protect them by getting vaccinated ourselves — when vulnerable people don't come into contact with the flu, they won't catch it. While babies under six months aren't yet old enough to receive a flu vaccine, their mothers can help guard them against influenza by receiving a flu shot during pregnancy. 

While nearly everyone should ideally get a flu shot, vaccination is even more important for the most vulnerable groups — children, older adults, pregnant women, and those with chronic respiratory conditions, cancer, heart conditions, diabetes, and many other chronic medical problems. 

Ask your doctor which flu vaccine is right for you:

  • The vaccine simply known as "the annual flu shot" comes in a few different forms — including the inactivated influenza vaccine (IIV) and recombinant influenza vaccine (RIV). The CDC doesn't recommend one over the other. 
  • The live attenuated influenza vaccine (LAIV4) is also known as the nasal spray flu vaccine. This contains live, weakened, viruses, and is approved for people between the ages of two and 49 who are not pregnant or immunocompromised. 
  • The high-dose flu vaccine is four times more potent, and is approved for people over the age of 65. 

Is the flu shot safe? Well, you may experience some soreness at the injection site, muscle aches, or a headache. Rare complications, like Guillain-Barre syndrome (which more often results from the flu itself) are possible but unlikely. Half a century of research has shown and keeps showing, however, that the flu vaccine has an excellent safety record. It is the most effective way to protect yourself against the flu. 

How can you guard yourself against a common cold?

The same steps that will help prevent the flu will also minimize your risk of catching a cold. These include:

  • Washing your hands often and properly, especially after spending time in public places with lots of people. 
  • Not touching your face with unwashed hands. 
  • Disinfecting surfaces such as doorknobs, keyboards, and lift buttons often. 
  • Staying away from people who have a cold. 

Given the fact that the cold can be caused by so many different viruses there is, however, no vaccine against the common cold — not yet, anyway. Thankfully, the cold is much less likely to lead to serious complications than influenza, so for now, we may have to accept that it's going to plague us from time to time. 

Treatment: What should you do if you suspect you have a flu?

Did you know that you don't simply need to take to your bed with painkillers and hot tea and wait for influenza to pass if you are pretty sure you have the tell-tale symptoms? Antiviral medications that shorten the duration of the flu and make for milder symptoms are available, but they work best if they are administered within the first 48 hours of the onset of symptoms. That is why it is so important for people who suspect they have influenza to go to the doctor quickly, especially if they belong to one of the high-risk groups. Your doctor can give you a rapid flu test and offer you one of the following (prescription-only) antivirals if you indeed have the flu:

  • Amantadine (Symmetrel)
  • Rimantadine (Flumadine)
  • Zanamivir (Relenza)
  • Oseltamivir (Tamiflu).

Adults should seek emergency medical care if they (think they) have the flu and notice any of the following symptoms:

  • Shortness of breath or trouble breathing
  • Chest pain or abdominal pressure that won't go away
  • Lethargy, confusion, or dizziness
  • Lack of urination
  • Seizures
  • Extreme physical weakness
  • Severe muscle aches
  • An acute worsening of the symptoms of a chronic medical condition
  • Fever and cough that get better but then suddenly worsen again

In children, the warning signs that point to a need for emergency medical care include:

  • Breathing difficulties (fast breathing is one sign)
  • Blue-tinted lips or face
  • Severe muscle or chest pain
  • No urine, no tears, and a dry mouth, which point to dehydration — something potentially very serious
  • You can't wake the child up
  • Seizures
  • In infants younger than 12 weeks, any fever, and in older children, a fever of 104°F or higher
  • Symptoms that improve but worsen again
  • The child has an underlying chronic condition
Outside of these emergency situations, getting as much rest as you can, taking fever reducers and painkillers (ibuprofen or Tylenol, for instance), and drinking plenty of water will help you as you overcome the flu. Never give aspirin to children under 16, as this is associated with an increased risk of Reye's syndrome. Do not go out unless you absolutely can't avoid it, such as to see the doctor or go to the pharmacy. In these cases, wear a face mask to protect others and take care not to touch surfaces with unwashed hands. 

How should I manage a cold?

The treatment of common colds focuses on symptom relief. You can, again, take an analgesic and fever reducer to feel better. Antihistamines can help you fight nasal congestion, as can nasal decongestants. Expectorants, which help you cough more to clear mucus, may help you if your cold is preventing you from sleeping. Nasal steroid sprays can help you if you have a runny nose, while throat lozenges may relieve a sore throat. 

Can home remedies help me?

Honey has been shown to have antimicrobial properties as well as the potential to relieve a sore throat, so adding some honey to a hot lemon drink may help you feel better. Steam inhalation therapy can help you clear nasal congestion, as well. The most important "home remedy" may, however, simply be to stay hydrated and take it easy. 

Antibiotics do not help against influenza and colds!

Because they are both caused by viruses, while antibiotics are designed to work against bacterial infections, antibiotics won't help cure your cold or flu. Do not ask your doctor to prescribe you antibiotics for either, and do not take anyone else's antibiotics, or you will be contributing to the global health concern of antibiotic resistance. 

Back to top