How Long Does the Flu Last? Stages & Symptoms

Key takeaways

• The flu is a respiratory virus affecting the throat, nose, and sometimes the lungs.

• It typically takes about two weeks to recover from the flu.

   

• You are contagious two days before symptoms appear and up to seven days after they appear.

   

When symptoms like a sore throat and stuffy nose set in, you often wonder two things: What is this, and how long will it last? You could be dealing with allergies, a cold, or the flu, and each has a different timeline. How long the flu lasts depends on your general health but in general usually lasts about one to two weeks.

In this article, we break down the lifecycle of the flu, including how long you may experience symptoms, when you are contagious, and how long you should avoid interacting with others. We also advise when you should consider seeing a doctor. 

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How Long the Flu Lasts

The influenza virus causes the flu, a contagious respiratory sickness that affects the throat, nose, and sometimes the lungs. For healthy individuals, the flu is typically a fairly short-term illness, lasting no longer than a week or two. Luckily, you won’t feel miserable the entire time. Below is a timeline of a bout of the flu.

Incubation period

The time from when you’re exposed to a virus until symptoms first begin is called the incubation period. For the flu, this takes one to four days, with an average of two days. This means you may be contagious a day or two before symptoms start and can unknowingly spread the virus during that time.

Symptoms appear

Symptoms like cough, sore throat, fever, and runny nose generally show up one to four days after being exposed to the influenza virus. Not everyone has the same symptoms, and certain symptoms, like vomiting and diarrhea, are more common in children or with certain strains of the flu. If your symptoms are severe or you are immunocompromised, consider seeking medical care at this time. 

Symptoms peak

Flu symptoms generally peak two to four days after they begin, then begin to gradually improve on their own. You are also most contagious three to four days after symptoms start. Symptoms may include:

• Fever or chills
• Cough
• Sore throat
• Runny or stuffy nose
• Body aches
• Headaches
• Fatigue

Symptoms taper off

For otherwise healthy individuals, flu symptoms typically begin tapering off five days after they start. However, coughing and a general “sick” feeling may last for more than two weeks, especially for the elderly and those with chronic lung disease. 

Recovery

With rest, over-the-counter (OTC) medications, and plenty of fluids, you’ll be on the road to recovery in no time. However, even as you begin to feel better, it’s important to stay away from others for a little while to ensure you don’t spread the flu. You are contagious from 5-7 days after symptoms emerge, so it’s best to stay home for a week after you first begin feeling sick. If fever is one of your symptoms, stay home for at least 24 hours after your fever is gone. 

How Long Are You Contagious?

The flu virus is thought to spread by tiny droplets released into the air when sick people cough, sneeze, or talk. These droplets land on surfaces others may touch or go directly into the other person’s eyes, nose, or mouth causing them to get sick. 

If you have the flu, you were contagious even before you had symptoms. Before people start feeling symptoms, they are contagious for one or two days. Once symptoms start, you are contagious for the first five to seven days after getting sick. People with weakened immune symptoms or children, may be contagious for even longer.  

How to Treat the Flu

Prompt treatment with antiviral drugs, within two days of getting symptoms, may lessen symptoms and shorten the duration of your sickness by one or two days. They may also prevent severe complications like pneumonia. Not everyone needs antiviral drugs but those with compromised immune systems or the elderly may benefit. 

If you have the flu, be sure to stay home and distance yourself from others. If you do need to go out for any reason, wear a mask, cover your coughs and sneezes with a tissue, and wash your hands frequently. Allow yourself plenty of time to rest and be sure to keep yourself hydrated. 

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When to See a Doctor

With proper self-care, the flu typically goes away on its own, especially if you are otherwise healthy.

However, certain high-risk people should seek medical care when they come down with the flu to help watch for and prevent any serious complications such as pneumonia.

This includes: 

• Adults 65 and older
• Anyone with chronic illnesses (especially those that affect the lungs or immune system)
• Pregnant people
• Very young children with severe symptoms

Antiviral medications can help make flu symptoms go away about one day faster.

However, these need to be started within 72 hours of symptoms appearing, they can have bothersome side effects, and they do not prevent serious complications like hospitalization, pneumonia, or death.

Your healthcare provider can help you determine if these medications are right for you.

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Frequently Asked Questions

What is the fastest way to recover from the flu?

The best thing you can do to recover from the flu as fast as possible is to stay hydrated, rest, and isolate. There is no cure for the flu, antibiotics are ineffective against it, and antiviral medications like oseltamivir (Tamiflu) only make symptoms go away about one day more quickly and can have side effects. Over-the-counter medications may provide some relief from symptoms, but they do not make the flu go away any faster.

How long does immunity to the flu last after getting sick?

Because there are so many different strains, it’s hard to say how long immunity to the flu lasts after getting sick. On the other hand, if you get the flu shot, you’re protected against multiple variations of the virus for about six months.

How long should you stay at home with the flu?

Because the flu easily spreads from person to person, it’s important to stay home when you may be contagious. Generally, this is from a day before and up to seven days after symptoms start. So stay home for a week after you first feel sick to help keep others safe.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions,
and medical associations. We avoid using tertiary references.

• Am I Still Contagious? (2018).
  https://www.cedars-sinai.org/blog/am-i-still-contagious.html

• Flu: What To Do If You Get Sick. (2021).
  https://www.cdc.gov/flu/treatment/takingcare.htm

• Flu Season. (2021).
  https://www.cdc.gov/flu/about/season/flu-season.htm

• Flu Symptoms & Diagnosis. (2021).
  https://www.cdc.gov/flu/symptoms/index.html

• How Flu Spreads. (2018).
  https://www.cdc.gov/flu/about/disease/spread.htm

• How Long Does the Flu Last? (2020).
  https://www.health.harvard.edu/staying-healthy/how-long-does-the-flu-last

• Preventive Steps. (2021).
  https://www.cdc.gov/flu/prevent/prevention.htm

• What Are the Benefits of Flu Vaccination? (2021).
  https://www.cdc.gov/flu/prevent/vaccine-benefits.htm

• Key facts about influenza (Flu). (2022.)
  https://www.cdc.gov/flu/about/keyfacts.htm

How Long Does the Flu Last? Duration of Symptoms, Contagion

In most cases, most of your flu symptoms should resolve within about a week. You are most likely to infect others while your major symptoms last. Some people can be contagious for longer.

Influenza, commonly referred to as “the flu,” is a highly contagious respiratory infection caused by the influenza virus.

According to the Centers for Disease Control and Prevention (CDC), an uncomplicated influenza infection will last from three to seven days in most people, including children. However, a cough and feelings of weakness or fatigue can last for two weeks or longer.

Some people are at an increased risk for developing flu-related complications. These can include:

• pneumonia
• bronchitis
• sinus infections
• ear infections

These complications can be due to influenza virus in itself or because of a secondary bacterial infection. Serious flu-related complications can lead to hospitalization and even death.

Additionally, flu infection may make preexisting conditions worse. For example, if you have asthma, you may experience more severe asthma attacks while you have the flu.

You’re at increased risk for developing flu-related complications if you:

• are 65 years old or older
• are younger than 5 years old and particularly younger than 2 years old
• are of Native American (American Indian or Alaska Native) descent
• are pregnant or two weeks postpartum
• are extremely obese (BMI of 40 or more)
• live in a nursing home or long-term care facility
• have a weakened immune system, such as the kind seen in people with cancer or HIV
• have a chronic illness, such as asthma, diabetes, or COPD
• have a liver or kidney disorder

Do some strains of the flu last longer than other strains?

Although different influenza strains don’t generally affect the duration of illness, some strains (and subtypes of influenza A, like h4N2) can cause more severe illness than others.

According to the CDC, influenza A (h4N2) viruses have been associated with more hospitalizations and deaths in children and the elderly than other human influenza subtypes or strains, such as influenza A (h2N1) and influenza B.

Additionally, vaccine effectiveness for influenza A (h4N2) viruses has been generally lower.

Flu vs. cold duration

Despite having some overlapping symptoms, colds and the flu are two separate illnesses. Colds are typically milder than the flu. Cold symptoms will typically resolve in about 7 to 10 days and tend to not come on as fast as the flu. Flu symptoms may last for a couple of weeks.

Learn more about the differences between a cold and the flu.

It may take one to four days after exposure to the influenza virus for symptoms to develop.

If you have the flu, you’ll be contagious one day before developing symptoms and up to five to seven days after becoming ill.

Younger children or people with a weakened immune system may be contagious for longer.

The influenza virus can also survive on surfaces, such as doorknobs and tables, for up to 24 hours. Viruses live longer on materials such as stainless steel, plastic, and other hard surfaces.

To avoid transmitting the virus to others, wash your hands frequently and avoid touching your face or mouth.

If you’re sick, be sure to drink plenty of liquids and get plenty of rest. You can also take over-the-counter pain and fever relievers, such as ibuprofen (Advil) or acetaminophen (Tylenol), to help relieve your symptoms.

Stay at home while you’re sick and for at least 24 hours after your fever has gone down.

In some cases, your doctor may prescribe an antiviral medication. Antiviral medications can reduce the length of your illness and may help prevent complications. They don’t kill the influenza virus, however.

Antiviral medications must be taken within 48 hours of the onset of symptoms in order to be effective.

Common antiviral prescriptions include:

• zanamivir (Relenza)
• oseltamivir (Tamiflu)
• peramivir (Rapivab)

The U.S. Food and Drug Administration (FDA) also approved a new medication called baloxavir marboxil (Xofluza) in October 2018.

Receiving the flu vaccine can help prevent influenza infection from occurring in the first place. The vaccine won’t give you the flu.

There isn’t current scientific evidence supporting the effectiveness of natural products or home remedies against the flu.

Most flu symptoms will typically resolve within a week. However, the flu can cause serious complications in groups with known risk factors or people who have preexisting conditions.

If you or your child experience any of the following symptoms, seek medical attention immediately:

Adults

• trouble breathing or shortness of breath
• pressure or pain in chest or abdomen
• dizziness that comes on suddenly
• confusion
• vomiting
• symptoms that seem to improve, but then return or worsen

Infants and children

• trouble breathing, or breathing quickly
• not getting enough fluids
• not being able to eat
• not waking up
• not interacting or not wanting to be held
• skin that’s blue in color
• fever that comes with a rash
• fewer wet diapers than usual
• symptoms that seem to improve, but then return or worsen

If you come down with the flu, your symptoms will typically resolve on their own within a week. Prescribed antiviral medication may reduce this duration.

But if you have a high risk for complications or start to experience the more severe symptoms outlined above, contact your doctor right away.

incubation period for various types of infections, disease prevention measures

Almost every person on the planet suffers from 1 to 15 (average 4) episodes of SARS annually. ¹ The high incidence is due to the fact that respiratory viruses are numerous, variable and highly contagious. The spread of infections contributes to the neglect of prevention.

At an early stage, patients often do not realize that they can infect healthy people, and do not take protective measures. And after a few days of illness, many are sure that they no longer secrete viruses. In the article, we found out how long a person is contagious with ARVI, and when it is possible to contact others without risk.

Incubation period for different types of SARS

SARS is a broad group of viral infections. Despite the different types of pathogens (about 200 types ² studied), they have similar ways of spreading, development mechanisms and symptoms. All SARS affect the upper respiratory system, and their typical symptoms are runny nose, sneezing, coughing, sore throat and fever.

About half of all ARVI pathogens are rhinoviruses. ² Influenza, parainfluenza, coronaviruses, adenoviruses, respiratory syncytial viruses are common. Sometimes with ARVI, several pathogens are isolated simultaneously – in these cases, the disease is more severe. ³

As for the incubation period, it depends not only on the properties of the pathogen, but also on the characteristics of the organism and the strength of the immune response. Most often, from the moment of infection with SARS to the appearance of the first symptoms, it takes from 2 days to a week. ³ The main danger is that even in the absence of signs of infection, the patient can infect others.

When a person ceases to be contagious with SARS

When the virus enters the body, it attaches to the shell of a healthy cell, penetrates through it and begins to multiply. At the next stage, the daughter virions leave the infected cell and actively spread throughout the body, infecting new cells. This cycle is repeated many times until a sufficiently large number of viruses accumulate in the body. On average, this occurs on the 3rd day after infection. During this period, the patient poses the greatest danger to others, since coughing and sneezing releases the maximum amount of viruses. As a rule, the symptoms of the disease on this day are especially pronounced. ³

Antiviral drug of direct action – Nobasit ^® Forte – acts immediately after the virus enters the body. The active substance of the drug, enisamia iodide, prevents the penetration of the virus into cells by blocking the hemagglutinin protein. ⁴ Doctors recommend starting the drug within the first 48 hours of the onset of the disease to limit the spread of infection throughout the body and prevent infecting others. Due to the proven directed action on the cause of SARS, enisamia iodide helps to reduce the severity of the main clinical symptoms – cough, runny nose, nasal congestion, etc., and helps to reduce the duration of the disease. ⁵

Active release of viruses into the environment continues for several days. On the 5th day from the onset of the disease, specific antibodies against the pathogen are produced. Shedding of viruses is drastically reduced, and the chance of infecting others is reduced. By this time, the symptoms of SARS are weakening. This happens in most cases, but sometimes a recovered person remains contagious for up to 14 days – until the pathogen is completely removed from the body. ³

It can be said that a person stops spreading the infection about two weeks after the onset of the disease and can come into contact with healthy people without risk. Although usually the isolation of viruses stops earlier – with the disappearance of symptoms of SARS. But the timing of contagiousness depends on the type of infection.

Influenza

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With influenza, a person becomes a carrier of the virus immediately after infection. The duration of the illness is usually 5-7 days. Most patients stop shedding the virus when symptoms disappear, but about 20% of people remain contagious for another 10 to 16 days.

How to identify the flu. The infection spreads mainly by airborne droplets and occurs with a high temperature (38˚C and above), severe intoxication (headache, body aches, weakness). Nasal congestion and coughing often follow these symptoms. Epidemic outbreaks most often occur in the autumn-winter period.

Rhinovirus infection

⁹

The incubation period of rhinovirus does not exceed a week, and averages 1-3 days, while the disease lasts about 3-7 days. From the time of onset of symptoms, a person is contagious for 5–9days and another 2 days after the disappearance of symptoms.

How to recognize rhinovirus. The leading symptom is a runny nose with profuse discharge of mucus from the nose. Patients may have a reddened throat, a superficial cough may occur. The temperature rises slightly (up to 37.5˚C), signs of intoxication are absent or mild. Adults get sick more often than children. The peak incidence occurs in autumn and spring.

Adenovirus infection

¹⁰

With adenovirus, the duration of the incubation period is 1–12 days. Symptoms can appear from three days to several weeks. Depending on the form of the disease, a recovered person can spread the infection from 3-16 days. In children, this period can increase up to one and a half months, in people with immunodeficiency – up to three months.

How to identify adenovirus. It is transmitted by airborne droplets and household contact – through contaminated household items, toys, surfaces. The disease is manifested acutely – high (more than 38˚C) temperature, often signs of intoxication. The patient is concerned about wet cough and runny nose, conjunctivitis (redness, pain in the eyes, watery eyes), diarrhea. Many have swollen lymph nodes. Children get sick more often. Outbreaks can occur all year round (including summer).

SARS prevention measures

The main route of transmission of viral infections is airborne. When coughing, sneezing and talking, a sick person releases viruses that are contained in particles of saliva and mucus. Due to their very small size (much smaller than bacteria), ARVI pathogens remain longer in the aerosol and spread over long distances (up to 2–3 m). ¹¹

When the aerosol settles, the droplets dry up and most viruses die. But some of them retain viability and pathogenic properties for a long time. For example, adenoviruses can live outside the human body for up to 14 days. ² So, in addition to airborne droplets, the air-dust transmission route (by inhalation of dust that contains viruses) cannot be ruled out. Adenoviruses and rhinoviruses can also be spread by contact. The pathogen is transmitted through contaminated hands and household items.

Given the methods of transmission of diseases, during periods of seasonal outbreaks of incidence (for most SARS this is autumn, and for influenza – winter), precautions should be taken.

● Try to reduce the use of public transport and, if possible, avoid crowded places.

● When outdoors, do not touch your face with your hands.

● Wash your hands frequently or treat them with antiseptic solutions.

● At home, regularly carry out wet cleaning, ventilate the rooms.

● Dress for the weather, don’t overcool.

● If someone in the family is already sick, give him a separate room, individual dishes, limit contact with him.

● Try to lead a healthy lifestyle, eat well and consume enough vitamins – this will help maintain a strong immune system.

Briefly about the main

➢ More than 200 ARVI pathogens are known. Respiratory infections caused by different viruses have common features and differences, but the incubation period depends not only on the properties of the pathogen, but also on the characteristics of the body and the strength of the immune response.

➢ Especially dangerous are contacts with a sick person in the first 3 days after infection – it is during this period that symptoms usually appear most clearly.

➢ As symptoms improve, the risk of infection decreases, but finally disappears after about 2 weeks from the onset of the disease, but this period depends on the type of infection.

➢ In order not to get infected during colds, try to avoid crowded places, use a protective medical mask correctly, change it in time, do not touch your face on the street, wash your hands more often and use antiseptics, dress according to the weather and lead a healthy lifestyle.

➢ On indications (after consulting a doctor), take antiviral drugs.

Bibliography:

¹ Kovtun T. A., Tutelyan A. V., Shabalina S. V. Modern ideas about the epidemiology and etiology of acute respiratory diseases in children // Epidemiology and vaccine prevention. – 2010. – No. 5.

² Larina V. N. et al. Acute respiratory viral infections and influenza: etiology, diagnosis and treatment algorithm. – RMJ. Medical review. — 11.09.2019. – No. 9 (1).

³ Belan E. B., Sadchikova T. L. Acute respiratory viral infections: an actual look at the problem and a modern approach to treatment // BC. Medical review. — 12/25/2018. – No. 11.

⁴ Instructions for medical use (Nobasit®, film-coated tablets 250 mg; RU: LP-003508 dated 03/16/2016)

⁵ Lioznov D.A., Karnaukhova E.Yu., Zubkova T.G., Shakhlanskaya E.V. Evaluation of the effectiveness of the ARVI treatment regimen, including etiotropic (enisamia iodide) and symptomatic therapy // Therapeutic archive No. 3 – 2020 ⁸ Belan Yu.B., Starikovich M. V. Influenza A / California / 2009 (h2N1) in children // Attending physician – No. 10, 2009 – https://elibrary.ru/item.asp?id=18937511

⁶ Belan Yu.B., Starikovich M.V. Influenza A / California / 2009 (h2N1) in children // Attending physician – No. 10, 2009 – https://elibrary.ru/item.asp?id=18937511

⁷ Orlova N.V. Flu. Diagnosis, strategy for choosing antiviral drugs // Medical Council – No. 20, 2017 – https://cyberleninka.ru/article/n/gripp-diagnostika-strategiya-vybora-protivovirusnyh-preparatov

⁸ Biology of pathogens and control of influenza and SARS / Smirnov V.S. (and other authors) – St. Petersburg: Hippocrates, 2020 – 336 p.

⁹ Rhinovirus infection / Mikhailova E.V. (and other authors) // Infectious Diseases – V.14, No. 3, 2016 – https://elibrary.ru/item.asp?id=27241321

¹⁰ Loeb M, Kuchar E. Human Adenovirus Infections. McMaster Textbook of Internal Medicine. Krakow: Medycyna Praktyczna – https://empendium. com/mcmtextbook/chapter/B31.II.18.1.16.

¹¹ Pozdnyakova M. G., Shelekhova S. E., Erofeeva M. K. Epidemiology of acute respiratory viral infections and the possibility of their prevention // Portal Eurolab.

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Hepatitis

About the diagnosis and treatment of this type of disease

in children can be contacted by phone (8652) 24-13-61 (children’s department, head) – children’s hepatological center.

in adults – by phone (8652) 24-44-75 (adult department, head Olga Anatolyevna Kostenko) – adult hepatology center with outpatient reception.

What is hepatitis?

Viral hepatitis is a common and dangerous infectious disease. They can manifest themselves in different ways, but among the main symptoms are jaundice and pain in the right hypochondrium. To diagnose hepatitis, you need to do a blood test, urine test, and in difficult cases, a liver biopsy.

Of all forms of viral hepatitis, hepatitis A is the most common. From the moment of infection to the appearance of the first signs of the disease, it takes from 7 to 50 days. Most often, the onset of the disease is accompanied by a rise in temperature and may resemble the flu. Most cases end spontaneously and do not require active treatment. In severe cases, droppers are prescribed to eliminate the toxic effect of the virus on the liver.

The hepatitis B virus is transmitted sexually, by injection with non-sterile syringes in drug addicts, from mother to fetus. In typical cases, the disease begins with fever, weakness, joint pain, nausea and vomiting. Sometimes there are rashes. There is an increase in the liver and spleen. There may also be darkening of the urine and discoloration of the stool.

Hepatitis C is the most severe form of viral hepatitis, also called post-transfusion hepatitis. This means that they fell ill after a blood transfusion. This is due to the fact that testing of donated blood for the hepatitis C virus began only a few years ago. Quite often, infection occurs through syringes in drug addicts. Sexual transmission is also possible from mother to fetus. The greatest danger is the chronic form of this disease, which often turns into cirrhosis and liver cancer. Chronic course develops in approximately 70-80% of patients. The combination of hepatitis C with other forms of viral hepatitis sharply aggravates the disease and threatens with a fatal outcome.

Prevention of hepatitis.

To protect yourself from infection with hepatitis, you must follow simple rules.

Do not drink unboiled water, always wash fruits and vegetables, do not neglect the heat treatment of food. In this way, you can prevent infection with hepatitis A, the transmission of which is associated with contamination of food with the faeces of a sick person. The great rule “Wash your hands before eating” is a guarantee of health in this case too.

In general, contact with other people’s body fluids should be avoided. For protection against hepatitis B and C – primarily with blood. In microscopic quantities, blood can remain on razors, toothbrushes, nail scissors. Do not share these items with other people.

In medical institutions, measures are taken to prevent infection with hepatitis. However, if you had an endoscopy or dental treatment ten to fifteen years ago, when the fight against hepatitis was not yet carefully organized, you need to get checked. There is still a small risk of infection today.

Never share syringes and needles for taking drugs. Never use non-sterile piercings and tattoos. Remember – the hepatitis virus is very tenacious and, in contrast to the AIDS virus, it persists in the external environment for a long time (sometimes up to several weeks). Invisible traces of blood can remain even on the straws used in the use of cocaine, so in this case, too, one should be wary of infection.

Hepatitis B is most commonly transmitted sexually, but hepatitis C can also be transmitted.