Table of ContentsView AllTable of ContentsCausesSymptomsComplicationsTreatment
Table of ContentsView All
View All
Table of Contents
Causes
Symptoms
Complications
Treatment
Influenza(the flu) and infectiousmononucleosis(mono) are common illnesses that share many overlapping symptoms, but these two illnesses have different causes and require different treatments. It is easy to mistake one for the other. Therefore, getting an accurate diagnosis is important to ensuring that you’re treating your illness properly.
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The FluInfluenza A and BTransmitted through droplets from the nose, mouth, throatMonoEpstein-Barr virus (EBV)Transmitted through saliva and other bodily fluids (such as blood and semen)
The FluInfluenza A and BTransmitted through droplets from the nose, mouth, throat
Influenza A and B
Transmitted through droplets from the nose, mouth, throat
MonoEpstein-Barr virus (EBV)Transmitted through saliva and other bodily fluids (such as blood and semen)
Epstein-Barr virus (EBV)
Transmitted through saliva and other bodily fluids (such as blood and semen)
Flu Causes
Of the four types of viruses that can cause the flu (influenza A, B, C, and D), influenza A and B are the most commonly spread from person to person. They are also the viruses responsible for the seasonal flu each year.
One way you can catch the flu is if someone infected with influenza will sneeze or cough directly onto an object or surface right before you touch it.Still, this is why frequent hand washing is one of the preventive measures against the flu.
1:51Click Play to Learn About the Symptoms of the Flu
1:51
Click Play to Learn About the Symptoms of the Flu
Understanding the Different Types of Flu
Mono Causes
However, other viruses can also cause this disease, including:
FluFeverCoughSore throatRunny or stuffy noseMuscle or body achesHeadachesFatigueVomiting and diarrheaMonoExtreme fatigueFeverSore throatHead and body achesSwollen lymph nodes in neck and armpitsRash
FluFeverCoughSore throatRunny or stuffy noseMuscle or body achesHeadachesFatigueVomiting and diarrhea
Fever
Cough
Sore throat
Runny or stuffy nose
Muscle or body aches
Headaches
Fatigue
Vomiting and diarrhea
MonoExtreme fatigueFeverSore throatHead and body achesSwollen lymph nodes in neck and armpitsRash
Extreme fatigue
Head and body aches
Swollen lymph nodes in neck and armpits
Rash
Flu Symptoms
People with the flu will often experience some or all symptoms within two days of being exposed to an influenza virus. People with the flu are most contagious (most likely to spread the flu) three or four days after their illness starts.
In uncomplicated cases, symptoms usually resolve within five to seven days. However, coughs and general feelings of illness may linger for up to two weeks after the infection.
Feveris not present in all cases of the flu, and should not be a determining factor to measure your level of sickness.
Symptoms of the Flu
Mono Symptoms
While symptoms of the flu generally appear soon after an infection, mono symptoms can present quickly or slowly. In some cases, people who have mono may not experience anysymptomsuntil four to six weeks after you were infected. Even still, symptoms of mono may not occur all at once or even at all.
If you do experience symptoms, they typically resolve within two to four weeks. However, extreme fatigue can last longer. Occasionally, symptoms may persist for up to six months.
EBV is one of the most common viruses found all over the world. In fact, most people will become infected with EBV at some point in their lives, but they may not have any symptoms.Symptom-free (asymptomatic) people carrying the virus can still transmit the virus and infect others.
EBV is one of the most common viruses found all over the world. In fact, most people will become infected with EBV at some point in their lives, but they may not have any symptoms.
Symptom-free (asymptomatic) people carrying the virus can still transmit the virus and infect others.
Knowing the possible complications allows you to know what to watch for when you or your loved one has the flu or mono.
Flu ComplicationsDehydrationWorsening of underlying illnesses, such as diabetes, heart disease, asthma, and chronic obstructive pulmonary disease (COPD)Sinus or ear infectionPneumoniaMono ComplicationsEnlarged spleenTemporary liver inflammation (hepatitis) or jaundice (yellowing of the skin and eye whites)Reactivation of the virus
Flu ComplicationsDehydrationWorsening of underlying illnesses, such as diabetes, heart disease, asthma, and chronic obstructive pulmonary disease (COPD)Sinus or ear infectionPneumonia
Dehydration
Worsening of underlying illnesses, such as diabetes, heart disease, asthma, and chronic obstructive pulmonary disease (COPD)
Sinus or ear infection
Pneumonia
Mono ComplicationsEnlarged spleenTemporary liver inflammation (hepatitis) or jaundice (yellowing of the skin and eye whites)Reactivation of the virus
Enlarged spleen
Temporary liver inflammation (hepatitis) or jaundice (yellowing of the skin and eye whites)
Reactivation of the virus
Flu Complications
The flu is a common cause ofpneumonia, especially among younger children, the elderly, pregnant women, or those with certain chronic health conditions or who live in a nursing home. Most cases of the flu never lead to pneumonia, but those that do tend to be more severe and deadly.
Certain strains can lead to specific complications. Invasive infection withNeisseria meningitidiscan lead to meningococcal meningitis (the bacteria infect the lining of the brain and spinal cord and cause swelling).
Other possible complications include:
How the Flu Affects Babies
Mono Complications
Although unpleasant, most cases of mono are not life-threatening and do not usually cause serious complications.Since this is not true in all cases, we need to know what to watch for in rare occasions too.
Complications that occur in at least 1% of mono patients include:
We can sometimes still get sick even when we are careful about washing our hands, eating and resting well, and avoiding people who are sick with the flu or mono.
FluRest to help body fight infectionHydrate to help body flush out toxinsTake a pain reliever like Tylenol (acetaminophen) to reduce fever and body achesStay homeEat a light dietAsk about antiviral medications if severely illMonoRestHydrateTake NSAIDs or Tylenol (acetaminophen)Stay homeGargle with salt water and suck on lozengesAvoid sports to prevent spleen rupture
FluRest to help body fight infectionHydrate to help body flush out toxinsTake a pain reliever like Tylenol (acetaminophen) to reduce fever and body achesStay homeEat a light dietAsk about antiviral medications if severely ill
Rest to help body fight infection
Hydrate to help body flush out toxins
Take a pain reliever like Tylenol (acetaminophen) to reduce fever and body aches
Stay home
Eat a light diet
Ask about antiviral medications if severely ill
MonoRestHydrateTake NSAIDs or Tylenol (acetaminophen)Stay homeGargle with salt water and suck on lozengesAvoid sports to prevent spleen rupture
Rest
Hydrate
Take NSAIDs or Tylenol (acetaminophen)
Gargle with salt water and suck on lozenges
Avoid sports to prevent spleen rupture
Flu treatment
Children and adolescents with fevers should not take aspirin. It has been associated with a rare disorder that causes brain and liver damage (Reye’s syndrome).
Antiviral drugs are not the same as antibiotics, which are meant to kill bacteria. They are prescription-only medications that can:
They are most effective when taken early in the illness (within two days of getting sick).But you can still talk to your healthcare provider about them even if this period has passed.
The Best Treatment for the Flu Is PreventionProtecting yourself against several influenza A and B strains at once means getting the seasonal flu shot. Studies have shown that flu shots reduce flu illness risk between 40% and 60% during flu season.
The Best Treatment for the Flu Is Prevention
Protecting yourself against several influenza A and B strains at once means getting the seasonal flu shot. Studies have shown that flu shots reduce flu illness risk between 40% and 60% during flu season.
Mono Treatment
You treat mono at home with rest and plenty of fluids as well. Antibiotics and antiviral medications do not work for mono.
You should still call your healthcare provider or seek medical help if you have any of the following:
How Mononucleosis Is Treated
A Word From Verywell
13 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Types of influenza viruses.Centers for Disease Control and Prevention.Key facts about influenza (flu).Centers for Disease Control and Prevention.About infectious mononucleosis (mono).Centers for Disease Control and Prevention.How flu spreads.Centers for Disease Control and Prevention.Clinical signs and symptoms of influenza.John Hopkins Medicine.Infectious mononucleosis.Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).Cleveland Clinic.Mononucleosis.Balfour HH, Dunmire SK, Hogquist KA.Infectious mononucleosis.Clinical & Translational Immunology. 2015;4(2):e33. doi:10.1038/cti.2015.1.xCleveland Clinic.Influenza (flu).Centers for Disease Control and Prevention.Flu & young children.Centers for Disease Control and Prevention.Treatment: what you need to know.Centers for Disease Control and Prevention.Benefits of the flu vaccine.
13 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Types of influenza viruses.Centers for Disease Control and Prevention.Key facts about influenza (flu).Centers for Disease Control and Prevention.About infectious mononucleosis (mono).Centers for Disease Control and Prevention.How flu spreads.Centers for Disease Control and Prevention.Clinical signs and symptoms of influenza.John Hopkins Medicine.Infectious mononucleosis.Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).Cleveland Clinic.Mononucleosis.Balfour HH, Dunmire SK, Hogquist KA.Infectious mononucleosis.Clinical & Translational Immunology. 2015;4(2):e33. doi:10.1038/cti.2015.1.xCleveland Clinic.Influenza (flu).Centers for Disease Control and Prevention.Flu & young children.Centers for Disease Control and Prevention.Treatment: what you need to know.Centers for Disease Control and Prevention.Benefits of the flu vaccine.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.Types of influenza viruses.Centers for Disease Control and Prevention.Key facts about influenza (flu).Centers for Disease Control and Prevention.About infectious mononucleosis (mono).Centers for Disease Control and Prevention.How flu spreads.Centers for Disease Control and Prevention.Clinical signs and symptoms of influenza.John Hopkins Medicine.Infectious mononucleosis.Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).Cleveland Clinic.Mononucleosis.Balfour HH, Dunmire SK, Hogquist KA.Infectious mononucleosis.Clinical & Translational Immunology. 2015;4(2):e33. doi:10.1038/cti.2015.1.xCleveland Clinic.Influenza (flu).Centers for Disease Control and Prevention.Flu & young children.Centers for Disease Control and Prevention.Treatment: what you need to know.Centers for Disease Control and Prevention.Benefits of the flu vaccine.
Centers for Disease Control and Prevention.Types of influenza viruses.
Centers for Disease Control and Prevention.Key facts about influenza (flu).
Centers for Disease Control and Prevention.About infectious mononucleosis (mono).
Centers for Disease Control and Prevention.How flu spreads.
Centers for Disease Control and Prevention.Clinical signs and symptoms of influenza.
John Hopkins Medicine.Infectious mononucleosis.
Centers for Disease Control and Prevention.About Epstein-Barr virus (EBV).
Cleveland Clinic.Mononucleosis.
Balfour HH, Dunmire SK, Hogquist KA.Infectious mononucleosis.Clinical & Translational Immunology. 2015;4(2):e33. doi:10.1038/cti.2015.1.x
Cleveland Clinic.Influenza (flu).
Centers for Disease Control and Prevention.Flu & young children.
Centers for Disease Control and Prevention.Treatment: what you need to know.
Centers for Disease Control and Prevention.Benefits of the flu vaccine.
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