The common cold and the flu may seem similar at first. They are both respiratory illnesses and can cause similar symptoms. But different viruses cause these two conditions. Your symptoms will help you tell the difference between the two.
Both a cold and the flu share a few common symptoms. People with either illness often experience:
- a runny or stuffy nose
- body aches
- general fatigue
As a rule, flu symptoms are more severe than cold symptoms.
Another distinct difference between the two is how serious they are. Colds rarely cause other health conditions or problems. But the flu can lead to sinus and ear infections, pneumonia, and sepsis.
To determine whether your symptoms are from a cold or from the flu, you need to see your doctor. Your doctor will run tests that can help determine what’s behind your symptoms.
If your doctor diagnoses a cold, you’ll only need to treat your symptoms until the virus has run its course. These treatments can include using over-the-counter (OTC) cold medications, staying hydrated, and getting plenty of rest.
Taking an OTC flu medicine early in the virus’ cycle may also help. Rest and hydration are also beneficial for people with the flu. Much like the common cold, the flu just needs time to work its way through your body.
What are the symptoms of the flu?
Common symptoms of the flu include:
Fever: The flu almost always causes an increase in your body temperature. This is also known as a fever. Most flu-related fevers range from a low-grade fever around 100°F (37.8°C) to as high as 104°F (40°C). Although alarming, it’s not uncommon for young children to have higher fevers than adults. If you suspect your child has the flu, see your doctor.
You may feel “feverish” when you have an elevated temperature. Symptoms include chills, sweats, or being cold despite your body’s high temperature. Most fevers last for less than one week, usually around three to four days.
Cough: A dry, persistent cough is common with the flu. The cough may worsen, becoming uncomfortable and painful. You may also experience shortness of breath or chest discomfort during this time. Many flu-related coughs can last for about two weeks.
Muscle aches: These flu-related muscle pains are most common in your neck, back, arms, and legs. They can often be severe, making it difficult to move even when trying to perform basic tasks.
Headache: Your first symptom of the flu may be a severe headache. Sometimes eye symptoms, including light and sound sensitivity, go along with your headache.
Fatigue: Feeling tired is a not-so-obvious symptom of the flu. Feeling generally unwell can be a sign of many conditions. These feelings of tiredness and fatigue may come on fast and be difficult to overcome.
Flu shot: Know the facts
Influenza is a serious virus that leads to many illnesses each year. You don’t have to be young or have a compromised immune system to get ill from the infection. Healthy people can get sick from the flu and spread it to friends and family. In some cases, the flu can even be deadly. Flu-related deaths are most common in people over age 65.
The best and most efficient way to avoid the flu and prevent spreading it is to get a vaccination. The flu vaccine is available as an injectable shot. The more people vaccinated against the flu, the less the flu can spread.
How does the flu shot work?
To make the vaccine, scientists select the strains of the flu virus that research suggests will be the most common in the coming flu season. Millions of vaccines with those strains are produced and distributed.
Once you receive the vaccine your body begins producing antibodies against those strains of the virus. These antibodies provide protection against the virus. If you come into contact with the flu virus at a later point, you can avoid an infection. You may get sick If you end up coming into contact with a different strain of the virus. But the symptoms will be less severe because you had the vaccination.
Who should get the flu shot?
Doctors recommend that everyone over the age of 6 months receive the flu vaccine.
This is especially true for people in high-risk categories, like:
- adults over age 65
- women who are pregnant
- children under age 5
- people with weakened immune systems due to chronic illness
Most doctors also recommend everyone gets their flu vaccine by the end of October. This way your body has time to develop the right antibodies before flu season kicks into gear. It takes about two weeks for antibodies to develop against the flu after vaccination.
How long does the flu last?
Most people will recover from the flu in about one week. But it may take several more days for you to feel back to your usual self. It’s not uncommon for you to feel tired for several days after your flu symptoms have subsided.
It’s important you stay home from school or work until you haven’t had a fever for at least 24 hours. This is without taking fever-reducing medications. If you have the flu, you’re contagious a day before your symptoms appear and up to five to seven days afterward.
Side effects of the flu shot
Many people report avoiding the flu vaccine each year for fear that it will make them sick. It’s important to understand that the flu vaccine can’t cause you to develop the flu. You aren’t going to become sick because you received the vaccine.
Flu vaccines contain dead or weakened strains of the flu virus. These strains aren’t strong enough to cause an illness.
You may experience some side effects from the flu shot. These side effects are often mild and only last a short period of time. The side effects of a shot outweigh the possible symptoms of a flu infection later.
The most common side effects of the flu shot include:
- soreness around the flu shot injection site
- low-grade fever in the days immediately following the injection
- mild aches and stiffness
Any side effects that do occur often only last a day or two. Many people won’t experience any side effects.
On rare occasions, some people may have a serious allergic reaction to the vaccination. If you’ve had an allergic reaction to any vaccine or medication before, talk with your doctor.
Treatment options for the flu
Most cases of the flu are mild enough that you can treat yourself at home without prescription medications.
It’s important you stay home and avoid contact with other people when you first notice flu symptoms.
You should also:
- Drink plenty of fluids. This includes water, soup, and low-sugar flavored drinks.
- Treat symptoms such as headache and fever with OTC medications.
- Wash your hands to prevent spreading the virus to other surfaces or to other people in your house.
- Cover your coughs and sneezes with tissues. Immediately dispose of those tissues.
If symptoms become worse, call your doctor. They may prescribe an antiviral medication. The sooner you take this medicine, the more effective it is. You should start treatment within 48 hours from when your symptoms start.
Contact your doctor as soon as symptoms appear if you’re at high risk for flu-related complications. These high-risk groups include:
- people with weakened immune systems
- women who are pregnant
- people over age 65
- children under age 5
Your doctor may test for the flu virus right away. They may also prescribe an antiviral medication to prevent complications.
When is flu season?
The main flu season stretches from late October to March. Cases of the flu peak during February. But you can get the flu at any time of the year.
You’re more likely to get sick during the fall and winter months. This is because you’re spending more time in close quarters with other people. And because you’re exposed to lots of different illnesses.
You’re more likely to catch the flu if you already have a different infection. This is because other infections can weaken your immune system and make you more vulnerable to new ones.
Remedies for flu symptoms
Being ill from the flu is no fun. But remedies for flu symptoms are available, and many of them provide great relief.
Keep these treatments in mind if you have the flu:
Pain relievers: Analgesics like acetaminophen and ibuprofen are often recommended to help ease symptoms. These include muscle aches and pains, headache, and fever.
Children and teens should never take aspirin for an illness. This is because of the risk of a rare, but fatal, condition called Reye’s syndrome.
Decongestants: This type of medication can help relieve nasal congestion and pressure in your sinuses and ears. Each type of decongestant can cause some side effects. So, be sure to read labels to find one that’s best for you.
Expectorants: This type of medication helps loosen thick sinus secretions that make your head feel clogged and cause coughing.
Cough suppressants: Coughing is a common flu symptom, and some medications can help relieve it. If you don’t want to take medication, some cough drops use honey and lemon to ease a sore throat and cough.
Be careful not to mix medications. Using unnecessary medications could cause unwanted side effects. It’s best to take medicines that apply to your predominant symptoms.
In the meantime, get plenty of rest. Your body is fighting hard against the influenza virus, so you need to give it plenty of downtime. Call in sick, stay at home, and get better. Don’t go to work or school with a fever.
You should also drink plenty of fluids. Water, juice, sports drinks, and soup can help you stay hydrated. Warm liquids like soup and tea have the added benefit of helping ease pain from a sore throat.
Flu symptoms in adults
Flu-related fever that appears in adults and can be severe. For many adults, a sudden high fever is the earliest symptom of a flu infection.
Adults rarely spike a fever unless they have a serious infection. The flu virus causes an abrupt high temperature that’s greater than 100°F (37.8°C).
Other viral infections, like a cold, may cause low-grade fevers.
Beyond this, children and adults share many of the same symptoms. Some people may experience one or several symptoms more than another person. Each person’s influenza infection will be different.
What’s the incubation period for the flu?
The typical incubation period for the flu is one to four days. Incubation refers to the period during which the virus is in your body and developing. During this time, you may not show any symptoms of the virus. That doesn’t mean that you aren’t contagious. Many people are capable of spreading the virus with others a day before symptoms appear.
The millions of tiny droplets produced when we sneeze, cough, or talk spreads the flu virus. These droplets enter your body through your nose, mouth, or eyes. You can also pick up the flu by touching a surface that has the virus on it and then touching your nose, mouth, or eyes.
Is there such a thing as the “24-hour flu”?
The “24-hour flu” is a common infection that has nothing to do with influenza, despite sharing a name. The 24-hour flu is caused by a family of viruses called norovirus.
The symptoms of a norovirus infection include:
- stomach cramping
These symptoms occur in the gastrointestinal system. That’s why the 24-hour flu is sometimes called a “stomach flu.” Although it’s called the “24-hour flu,” you may be ill up to three days.
Influenza (or the flu) is a respiratory illness. It causes symptoms in the respiratory system.
Symptoms of influenza include:
- runny nose
- body aches
The symptoms of the two are different. Some people with the flu may experience nausea and vomiting while they’re sick. But these symptoms aren’t as common.
Is the flu contagious?
If you have the flu, you’re contagious. Many people are contagious and can spread the virus as early as a day before they show symptoms. In other words, you may be sharing the virus before you even realize that you’re sick.
You may still be contagious five to seven days after your symptoms appear. Young children are often contagious for more than seven days after symptoms first appear. People who have a weak immune system may experience the virus symptoms longer, too.
If you have the flu, stay home. Do your part to prevent the spread of the virus to other people. If you’re diagnosed, alert anyone you came into contact with in the day before your symptoms appeared.
What is the flu?
Influenza or “the flu” is a common, infectious virus spread by infected droplets that enter another person’s body. From there, the virus takes hold and begins to develop.
Each year, the flu spreads across the United States. Winter is the flu’s primary season, with a peak in February. But you can be infected with the flu any time of the year.
Many strains of the flu exist. Doctors and researchers determine which strains of the virus will be most common each year. Those strains are then used to produce vaccines. A flu vaccine is one of the easiest and most effective ways to prevent a flu infection.
Is there medication for the flu?
Medications called “antiviral” drugs can treat the flu. These medications are available by prescription only. You must visit a doctor or healthcare provider to receive a prescription. You can’t buy these medicines over the counter at a pharmacy.
Antiviral medications used to treat the flu can help ease the symptoms. They can also shorten the length of the flu by a day or two. Taking antiviral medications may help if you get the flu. But these medications also have side effects.
Antiviral medications are important for people at high risk for developing complications from the flu.
People in this high-risk category include:
- children under age 5
- adults over age 65
- women who are pregnant
- people with chronic medical conditions that weaken their immune systems
Research suggests antiviral medications work best if you take them within 48 hours of having symptoms. If you miss that window, don’t worry. You may still see a benefit from taking the medicine later. This is especially true if you’re at high risk or are ill. Taking antiviral medications may help protect you against flu complications. These include pneumonia and other infections.
Early symptoms of the flu
Symptoms of the flu appear quickly. This sudden onset of symptoms is often the flu’s first hallmark. Similar illnesses, such as a cold, take several days for symptoms to emerge.
Another common early symptom of the flu is the breadth of pain. People with the flu report feeling uncomfortable all over their body as an early symptom.
You may feel as if you’ve been “hit by a truck.” Getting out of bed may prove to be difficult and slow. This feeling may be an early symptom of the flu.
After this, other symptoms of the flu may begin appearing, making it obvious you have the virus.
Are there natural flu remedies?
If left untreated, the typical flu often goes away in about one week. During that time, you have several treatment options for making symptoms easier to handle.
Prescription antiviral medicines can reduce the severity of the infection. It can also shorten its duration. Some OTC treatments can ease the symptoms of the infection. Even some natural flu remedies may be helpful for easing symptoms.
Some people may find natural flu remedies to be helpful. Medical research supports some treatments that include:
Soup: Warm chicken soup works on many levels as a flu remedy. The warm liquid can help ease sore throats and provide hydration and electrolytes. Studies have shown it can also change the movement of white blood cells in your body. This decreases inflammation.
Honey: A lot of “natural” cough and cold medicines contain honey. This is because it has antibacterial and antimicrobial properties. Honey is also an effective cough suppressant. Add some to your tea or eat a small spoonful if you’re trying to stop a coughing fit.
Ginger: Drop a few slices of ginger into your tea or a glass of warm water, and sip. This root has healing properties that can ease a sore throat and suppress a cough. It can also help with nausea.
Probiotics: Increase the good bacteria in your gut while your body is fighting an infection. A healthy gut microbiome can boost your immune system, prevent new infections, and promote healing.
Of course, rest is also an important part of recovering from a flu infection. Your body is fighting hard against the infection. It’s wise for you to stop, rest, and get more sleep so your immune system can fight back against the infection.
Written by Kimberly Holland
Medically Reviewed by Judith Marcin, MD