Flu (influenza): how to recognise it, treat it at home, and decide whether the vaccine is for you

Is it flu or a cold? How to tell the difference

Flu, short for influenza, is an infection of the nose, throat and lungs caused by influenza viruses. The quickest way to tell it apart from a common cold is speed and weight. Flu tends to hit suddenly, often within a few hours, with a high temperature, aching muscles and an exhaustion that sends you to bed. A cold creeps in over a day or two, stays mostly in the nose and throat, and rarely stops you working. The World Health Organization describes the typical picture as a sudden fever, cough, sore throat, body aches and fatigue, starting one to four days after infection and usually lasting around a week.

Most healthy adults and children recover from flu on their own. The illness is miserable but not dangerous for them, and the main job is rest, fluids and something to bring the fever down. The risk is concentrated in specific groups: pregnant women, people over 65, young children, and anyone living with diabetes, asthma, heart disease or another long-term condition. For them, flu can turn into pneumonia or make an existing illness suddenly much worse.

Two facts shape everything else on this page. First, flu is caused by a virus, so antibiotics, which only kill bacteria, do nothing against it. Second, the yearly flu vaccine is the most effective protection available, and it matters most for exactly the people who are most likely to end up in hospital.

Why flu season runs from October to March

In most Arab countries north of the equator, flu follows the northern hemisphere winter pattern. Cases start to climb in October or November, peak somewhere between December and February, and fade by March or April. Surveillance from Jordan shows the pattern clearly. Between January 2008 and February 2014, four sentinel hospitals tested 2,891 patients admitted with severe respiratory infections, and 9% had influenza. In ordinary, non-pandemic years, the share of positive tests peaked between November and January, reaching 14% to 42% of patients tested, and 8 of the 257 influenza-positive patients died.

The exact peak shifts from year to year and from country to country, so the announcements of your ministry of health are the best guide to when flu is circulating locally. A study of children under two admitted to hospital in Amman found the same thing: influenza was detected mainly between December and February, but the dominant strain changed from season to season. That changing strain is the reason the vaccine is updated every year.

Flu spreads through droplets when an infected person coughs, sneezes or talks, and through hands that touch a contaminated surface and then the eyes, nose or mouth. Adults are usually infectious from about a day before symptoms start until around five days after, and children for longer. Winter makes this easy: windows stay closed, families gather around one heater, classrooms are full and shared minibuses are crowded. One child bringing flu home from school can pass it to grandparents within a few days.

What a typical flu week looks like

Knowing the usual course helps you judge whether things are going as expected. After catching the virus, you feel normal for one to four days. Then symptoms arrive quickly: shivering, a temperature that may reach 39 degrees Celsius or more, a headache, aching back and legs, a dry cough and a sore throat. The second to fourth days are usually the worst, and many people cannot face getting out of bed.

By around day five the fever usually settles and appetite slowly returns. The cough and the tiredness are the stubborn parts. It is common to feel weak and to cough at night for one to two weeks after the fever has gone, and this alone is not a sign that something is wrong. What does matter is direction. A person who starts to improve and then gets worse again, with the fever returning, breathing becoming harder or new chest pain, may have developed a bacterial pneumonia on top of the flu and needs to be seen by a doctor.

Children often run higher fevers than adults and may also have vomiting, diarrhoea or ear pain. In a national study of 1,000 children under five admitted to four Jordanian hospitals during the 2022 to 2023 season, 9.9% tested positive for influenza, and those children had longer fevers and more sore throats than children admitted with other infections. Young children can become dehydrated quickly, so how much they are drinking is as important as the number on the thermometer.

How to treat flu at home: what actually helps

For most people, treating flu means supporting the body while the immune system clears the virus. Rest as much as you can, because pushing through flu usually makes it last longer. Drink regularly, little and often: water, warm soups, diluted juices and warm drinks all count. Keep the room comfortably warm but not stuffy, and air it a few times a day.

Paracetamol or ibuprofen can bring the temperature down and ease the aches, used according to the instructions on the pack or the advice of your pharmacist. Many cold and flu sachets sold in pharmacies already contain paracetamol, so check the label before you take a second product, because doubling up by accident is a common cause of paracetamol overdose. Aspirin should never be given to children or teenagers under 16, because of the risk of Reye syndrome, a rare but serious condition affecting the liver and brain.

There are antiviral medicines for flu, the best known being oseltamivir, sold as Tamiflu. Doctors usually prescribe them for people at high risk of complications or for anyone who is seriously ill, and they work best when started within 48 hours of the first symptoms. For a healthy adult they shorten the illness only modestly, so they are not a routine treatment. In some countries they are hard to find outside hospitals. If you belong to a high-risk group, call a doctor early in the illness rather than waiting to see how it goes.

Stay at home until your fever has been gone for at least 24 hours without the help of fever medicine. That protects your colleagues and classmates, and it also gives you a better chance of a quick recovery.

Why antibiotics do nothing for flu

Antibiotics kill bacteria. Influenza is a virus, and no antibiotic touches it. Taking one for flu will not bring the fever down sooner, will not stop you passing the virus on, and will not prevent complications in a healthy person. It does expose you to side effects such as diarrhoea, stomach pain, rashes and allergic reactions, and every unnecessary course helps bacteria in your body and your community learn to resist the antibiotics we will need later.

Despite this, antibiotics for flu-like illness are still the norm in much of the region. A review of 372 medical reports and prescriptions for employees of two companies in Greater Beirut, collected between 2017 and 2018, found that 82.0% of people diagnosed with flu-like symptoms were given an antibiotic. A separate study in the family medicine clinics of a university hospital in Amman found that only 28.8% of all antibiotics prescribed there were appropriate for the diagnosis.

In many countries you can buy an antibiotic at the pharmacy without a prescription, and a well-meaning pharmacist may hand one over with the flu sachets. It is reasonable to ask directly: is this an antibiotic, and why do I need it? Antibiotics do have a role when flu leads to a bacterial complication, such as pneumonia, a bacterial ear infection or sinusitis. That decision belongs to a doctor who has examined you, usually several days into the illness when things are getting worse rather than better.

Who is at high risk from flu?

For a fit 30 year old, flu is a bad week. For some people it is a genuine threat. The groups at highest risk are pregnant women, adults over 65, children under five and especially under two, and people of any age with a long-term condition: diabetes, asthma or chronic lung disease, heart disease, kidney or liver disease, severe obesity, or a weakened immune system from illness or medicines such as chemotherapy or long-term steroids.

Diabetes deserves special mention in this region, where it is very common. Flu can push blood sugar up sharply, and a fever with poor eating and vomiting can tip someone into a dangerous metabolic emergency. People with asthma often find flu triggers a severe attack. In older people, flu can bring on a heart attack or stroke in the weeks after the infection, not just pneumonia.

Pregnancy changes the immune system, the heart and the lungs in ways that make severe flu more likely, particularly in the later months. Babies under six months are too young to be vaccinated, so their protection comes from a mother vaccinated during pregnancy and from the people around them being vaccinated. The Jordanian study of 1,000 hospitalised children found no influenza at all among children who had been vaccinated or whose family members had received the vaccine, and its authors called for vaccination programmes aimed at young children and pregnant women.

The flu vaccine: who needs it and when to get it

The flu vaccine is updated every year to match the strains expected to circulate, so last year's dose does not cover this winter. The best time to have it is in autumn, from September to November, because the body needs about two weeks to build protection before flu peaks. Having it later in the season is still worthwhile. The injected vaccine contains no live virus and cannot give you flu. A sore arm and a day of mild aches are the usual side effects.

The World Health Organization recommends yearly vaccination above all for pregnant women, older adults, people with chronic illnesses, young children and health workers. Many ministries of health run free autumn campaigns for these groups through primary health centres, and private pharmacies and clinics often stock the vaccine as well. If it is not available where you live, ask your doctor or local health centre whether a campaign is planned and when supplies arrive.

Uptake across the region remains low. A nationwide survey of 1,650 adults in Saudi Arabia in December 2020 found that only 31.5% had received the flu vaccine in the 2019 to 2020 season, with higher uptake among people over 45 and those who understood their own risk. A review by the WHO regional office of a 2022 survey found that 14 countries in the Eastern Mediterranean Region, 64% of those reporting, had a national seasonal flu vaccine policy, and only 44% recommended the vaccine for all the target groups WHO advises.

The vaccine does not guarantee you will not catch flu, but vaccinated people who do catch it usually have a milder illness and are less likely to be admitted to hospital. It is safe at any stage of pregnancy. An egg allergy is rarely a reason to avoid it, but tell the nurse before the injection so they can choose the right product.

When flu becomes an emergency

Most flu can be managed at home, but some signs mean the infection has spread to the lungs, the body is running short of oxygen or fluids, or another serious illness is hiding behind the fever. These are reasons to go to an emergency department now, not to wait for the morning or for a clinic appointment. If transport is difficult, call your local emergency number or arrange a car rather than hoping it will pass.

In children, the warning signs can look different. Fast or noisy breathing, the skin between the ribs pulling in with each breath, blue or grey lips, unusual sleepiness or floppiness, refusing to drink, or no wet nappy for eight hours or more all need urgent care. A baby under three months with any fever should be seen by a doctor the same day.

Some situations are not emergencies but still need a doctor soon. Call if you are in a high-risk group and develop flu symptoms, so antivirals can be considered early. Call if you are not starting to improve after a week, if you get better and then worse, or if you are coughing up yellow, green or bloodstained phlegm.

How to stop flu spreading at home

Flu moves through a household quickly, so a few habits make a real difference. The sick person should stay home, sleep in a separate room if possible, and cough or sneeze into a tissue or the crook of the elbow. Everyone should wash their hands with soap often, especially before eating and after wiping noses. Open a window for a few minutes several times a day, even in cold weather, because fresh air dilutes the virus.

Do not share cups, glasses or spoons while someone is ill, including the shared tea glass or coffee cup that goes around a family gathering. Clean door handles, remote controls and phones daily. If there is a newborn, a pregnant woman or an elderly relative with a chronic illness in the house, the sick person should keep their distance, and wearing a mask when they must be close is sensible.

The strongest protection for a vulnerable relative is vaccinating the people around them. A grandmother with diabetes is safer when her children and grandchildren have all had this year's vaccine, and a baby too young for the vaccine is safer when parents and siblings have had it. Children can usually return to school when they have been free of fever for 24 hours without medicine and feel well enough to take part.

Sources

• World Health Organization: Influenza (seasonal) fact sheet
• Rolsma SL, Rankin DA, Haddadin Z et al: Assessing the epidemiology and seasonality of influenza among children under two hospitalized in Amman, Jordan, 2010-2013, Influenza and other respiratory viruses, 2021
• Al-Abdallat M, Dawson P, Haddadin AJ et al: Influenza hospitalization epidemiology from a severe acute respiratory infection surveillance system in Jordan, January 2008-February 2014, Influenza and other respiratory viruses, 2016
• Abu-Helalah M, Al-Shatnawi SF, Abu Lubad M et al: The Epidemiology and Health Burdens of Influenza Infections Amongst Hospitalized Children Under 5 Years of Age in Jordan: A National Multi-Center Cross-Sectional Study, Vaccines, 2024
• Lakkis NA, Alameddine R, Issa HG et al: Prescribing antibiotics in adults with respiratory tract infections in Lebanon, International journal of clinical practice, 2021
• Javed NB, Al-Mohaithef M: Socio-demographic determinants of influenza vaccination uptake behavior: A nationwide cross-sectional study in Saudi Arabia, Saudi medical journal, 2023
• Attia R, Abubakar A, Bresee J et al: A review of policies and coverage of seasonal influenza vaccination programs in the WHO Eastern Mediterranean Region, Influenza and other respiratory viruses, 2023