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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes, usually. Flu is diagnosed from the sudden onset and the symptoms by video, with antivirals prescribed for people at higher risk seen within 48 hours and a recovery plan for the rest; breathlessness, chest pain, confusion or a returning fever need in-person care.
- What it is: infection by influenza A or B viruses, which change every year; symptoms start 1 to 3 days after exposure, come on within hours, and in a typical European winter flu affects about 1 in 10 adults, with the season running from December to March.
- Timelines: contagious from the day before symptoms until about 5 days after, longer in children; fever lasts 3 to 5 days, the illness about a week, the cough and tiredness 1 to 2 weeks more; antivirals work only when started within 48 hours.
- Risk groups: people over 65, pregnant women, anyone with asthma, COPD, heart disease, diabetes, kidney or liver disease, a weakened immune system or severe obesity, and care-home residents are the groups offered antivirals and the yearly vaccine, because flu puts them in hospital.
- Not antibiotics: antibiotics do nothing against the flu virus and are prescribed only for a bacterial complication such as pneumonia or a chest infection, suggested by a fever that settles and then returns, breathlessness, chest pain or coughing green sputum or blood.
- Emergency: call 112 for severe breathlessness, chest pain, coughing blood, confusion or drowsiness, blue lips, a seizure, or being unable to stay awake, and go to in-person care without delay for passing very little urine or getting worse after starting to improve.
If you are breathless, have chest pain, feel confused or unusually drowsy, or are passing very little urine, arrange urgent in-person care instead of a video appointment. The same applies if you are pregnant, over 65 or living with a serious long-term condition and getting worse rather than better. For severe breathlessness, chest pain or confusion, call 112.
Can an online doctor treat flu?
Yes. On Mobi Doctor, a licensed doctor can assess flu over video, usually within 15 minutes. The doctor confirms the diagnosis, screens for complication risk, and prescribes antiviral treatment where it genuinely helps.[1] Severe breathlessness, chest pain or confusion needs emergency care, so call 112 rather than booking a video appointment.
Flu is also the illness where staying on the sofa is a clinical virtue: a video consultation spares you a feverish trip to a waiting room and spares the waiting room your virus, without losing the two things that matter, a proper risk assessment and a concrete plan.
Listen: Flu Treatment Online
The audio version of this topic from the Mobi Doctor podcast. Open the episode.
How an online consultation helps with flu
- Timing matters with flu: antiviral medicines work best when started within about the first 48 hours of symptoms.[1] A video appointment protects that window while you stay home and keep your germs out of a waiting room: you can see a doctor over video, usually within 15 minutes.
- Risk-group check: the doctor establishes whether pregnancy, age over 65, asthma, COPD, heart, kidney or liver disease, diabetes or a weakened immune system puts you in a group where flu deserves closer attention than "wait it out".
- A concrete plan for the week: what to take and when, how much to drink, roughly when the fever should break, and the specific warning signs that should bring you back or straight to in-person care.
- Protecting your household: concrete advice for homes with pregnant, elderly or chronically ill members, the people for whom your flu is a much bigger deal than it is for you, including what to watch for in them.
What the doctor checks in an online flu consultation
A flu consultation confirms the picture fits influenza, checks your risk, and watches your breathing. In a flu consultation the doctor will typically check:
- When symptoms started, ideally to the hour: the antiviral window of about 48 hours is real, and timing changes the options.[1]
- Whether the pattern fits flu: sudden onset, fever, muscle aches, headache and exhaustion, rather than a nose-centred cold.
- Your risk group: pregnancy, age over 65, asthma, COPD, heart, kidney or liver disease, diabetes, a neurological condition or a weakened immune system.
- Your breathing on camera, plus your temperature and any pulse-oximeter reading if you have them; both sharpen the assessment, though neither is required.
- Vaccination status this season.
- Your regular medicines and conditions, and how well controlled they are.
- Who you live with, since a vulnerable household changes the advice.
- A red-flag screen: breathlessness, chest pain, confusion, poor urine output, or a fever that returns after settling.
What is the difference between flu and a cold?
Flu starts abruptly, often within hours, with fever, muscle aches, headache and exhaustion that stops you working. A cold builds over a day or two, stays centred on a runny or blocked nose, sneezing and a scratchy throat, and usually leaves you able to carry on. Speed and severity are the giveaway.
Flu vs cold: symptoms at a glance
Swipe sideways to compare →
| Feature | Flu | Cold |
|---|---|---|
| How it starts | Suddenly, over hours | Gradually, over a day or two |
| Fever | Common, often high | Rare or mild in adults |
| Muscle aches | Marked, whole body | Slight |
| Exhaustion | Severe: bed, not desk | Mild |
| Sneezing, runny nose | Sometimes, in the background | The main event |
| Able to carry on? | Rarely | Usually |
| Typical course | About a week, then lingering cough and tiredness | A few days to a week |
Why the difference matters
A cold needs nothing but self-care and patience. Flu changes decisions: it is the illness where antiviral treatment exists, where risk groups need prompt assessment, and where complications such as pneumonia are worth actively watching for rather than discovering late.
Is my flu suitable for online care?
Most flu is safe to assess and plan online; a minority needs in-person care. The table below shows how doctors sort flu presentations into self-care, antiviral treatment where it is appropriate, and referral.
Swipe sideways to compare →
| Flu presentation | Likely first step | Suitable for online care? | When referral or in-person care is needed |
|---|---|---|---|
| Otherwise healthy adult, typical flu, seen early | Confirm flu, self-care plan, consider antiviral if early and appropriate | Usually yes | If breathlessness, chest pain, confusion or dehydration appears |
| Risk group (pregnant, over 65, chronic condition) within 48 hours | Prompt assessment; antiviral where the criteria are met[1] | Usually yes, promptly | Deterioration, or the underlying condition destabilising |
| Fever that returns after improving, or breathless on mild effort | Assess for a bacterial complication such as pneumonia | Sometimes, for triage | Chest examination or X-ray in person |
| Severe breathlessness, chest pain, confusion, very little urine | Emergency care | No | Call 112 immediately |
| High fever with stiff neck, new rash or intolerance of light | Emergency care (possible meningitis) | No | Call 112 immediately |
Not sure if you are in a higher-risk group? A doctor can tell you in one consultation.
See available times →Who should see a doctor promptly about flu?
Anyone pregnant, aged over 65, or living with a chronic condition such as asthma, COPD, heart, kidney or liver disease, diabetes, a neurological condition or a weakened immune system, should consult a doctor within the first day or two of flu symptoms. These groups benefit most from early antiviral treatment and closer monitoring.
The reason is complication risk: in these groups flu more often turns into pneumonia or destabilises the underlying condition, and early treatment plus a clear monitoring plan changes outcomes. One sign matters for everyone, risk group or not: a fever that settles and then returns days later can mark a secondary bacterial infection, and deserves same-day review.
Antivirals, antibiotics and the vaccine: an honest guide
Antiviral medicines
Flu antivirals (oseltamivir-type medicines) are real but modest: started early, ideally within 48 hours, they typically shorten the illness by around a day and are mainly reserved for people at higher risk or with severe illness.[1][4] They are doctor-assessed, not routine, and the doctor will tell you plainly what is possible for you.
The assessment itself weighs three things: how many hours since symptoms began, whether you belong to a risk group, and how severe the illness looks on camera. If you fall outside the window or the criteria, the doctor will say so and put the effort into the plan that actually helps, symptom control and monitoring.
Antibiotics and the flu vaccine
Antibiotics do not work against flu; it is a viral illness, and antibiotics are only prescribed when there are signs of a bacterial complication such as pneumonia, because unnecessary courses fuel antibiotic resistance.[3] Looking further ahead, the annual flu vaccine remains the best protection and is recommended across Europe for risk groups and health workers;[2] in many EU countries you can arrange it at a local pharmacy, and the doctor can advise whether you should.
How long does flu last?
Flu typically lasts about a week: the fever and worst aches peak in the first two to three days and settle within seven, while the cough and tiredness often linger one to two weeks longer.[5] Go back to work once the fever has been gone a full day and you can function.
That lingering phase deserves a word: a dry post-flu cough alone, slowly improving, is expected and does not need antibiotics. What breaks the pattern, and warrants review, is deterioration after improvement, breathlessness, or exhaustion that is getting deeper rather than lifting in week two.
Spanish readers can follow the same recovery timeline in how long flu lasts, day by day (in Spanish) on SíntomasGripe.
When it might be something else
COVID-19 and other winter viruses
Flu, COVID-19 and RSV overlap heavily, with fever, cough, aches and exhaustion, and no doctor can reliably separate them by symptoms alone. A rapid test, sold by pharmacies across Europe, is the only dependable way to tell, and the result is worth having: it changes isolation advice and, in risk groups, treatment options. Self-care is the same either way.
Early pneumonia
Suspect a bacterial complication rather than flu itself when someone gets worse after getting better, becomes breathless on mild effort, develops one-sided chest pain on breathing, or coughs up rust-coloured phlegm. This is the scenario the safety-netting exists for: same-day assessment, in person where examination is needed.
When fever is not flu
A high fever with a severe headache, a stiff neck, a new rash, or intolerance of light is not a flu pattern; those features raise meningitis and need emergency care immediately, not a video appointment. Call 112 if they appear.
Special situations
Flu in pregnancy
Pregnancy makes flu complications more likely at every stage, which changes two decisions: consult promptly rather than waiting it out, and take prevention seriously, because flu vaccination during pregnancy is recommended across Europe and protects the baby in the first months too. Antiviral treatment can be considered in pregnancy; that judgement belongs to the doctor, made case by case after assessment.
Flu when you are over 65
Older adults do not always run textbook fevers; flu can instead show as new confusion, unsteadiness, falls or simply "not themselves", sometimes with a normal thermometer reading. Families often spot it first. The threshold for a same-day review is lower here: deterioration in an older adult with flu is a today problem, not a tomorrow one.
Flu while travelling
Flu seasons differ by hemisphere: Europe's winter peak has a southern-hemisphere mirror in the middle of the year, and travellers meet flu out of season more often than they expect. A video consultation works wherever in Europe you are: English-speaking assessment, a prescription to a nearby pharmacy, and honest advice on when a local clinic is the better option. If in-person care is needed, a European Health Insurance Card (or its travel-insurance equivalent) smooths access to public healthcare across the EU, worth locating in your luggage before you are ill enough to need it.
Treatment options for flu
What you can do yourself
Rest is genuinely part of the treatment, so plan for several days, not one. Drink regularly (fever steadily drains fluid out of you), take paracetamol or ibuprofen for fever and aches, and stay home while feverish so you do not hand the virus on. Ventilate shared rooms, wash hands often, and keep your distance from household members in risk groups while you are at your most infectious in the first days; separate towels and, if you are caring closely for someone vulnerable, a mask in shared rooms are simple and worthwhile.
Managing the fever properly
Take paracetamol or ibuprofen at the intervals on the packet rather than waiting for the fever to spike; steady control feels dramatically better than peaks and troughs, and the two can be alternated if one alone is not enough, within each medicine's daily limit. Judge hydration by your urine: pale means you are winning, dark and scanty means drink more. Shivering under a duvet mid-fever is fine; what matters is fluid in and warning signs watched.
Prescription treatment
A prescription is never issued without a consultation. Where the assessment supports it, for higher-risk patients, severe symptoms or early presentation, the doctor can prescribe antiviral treatment and arrange follow-up to check you are on the right track. If your story or your recovery suggests a bacterial complication, they will either prescribe an antibiotic where the signs support it or direct you to in-person care for a chest examination first.
When flu is treated online, and when you need in-person care
Treated online: typical flu in otherwise healthy adults who need a plan and safety-netting; risk-group patients seen early enough to consider antiviral treatment; post-flu cough and tiredness that are slowly improving; and advice for protecting a vulnerable household.
In-person care: severe breathlessness, chest pain, confusion or very low urine output, which are emergencies; a fever with a stiff neck, new rash or intolerance of light, which raises meningitis and is an emergency; signs of pneumonia that need a chest examination in person; and older adults or pregnant patients who are deteriorating, where a lower threshold for in-person review applies. In those cases the consultation gets you to the right level of care quickly, not a prescription in place of one.
When to get in-person care
Seek urgent in-person care if you become breathless, cough up blood, cannot keep fluids down, are passing very little urine, or if fever returns after you had improved. If you have severe difficulty breathing, chest pain, confusion or unusual drowsiness, a fever with a stiff neck or new rash, or your lips turn blue or grey, call 112 immediately.
Treating flu at home: what helps and what does not
For most healthy adults, flu is miserable but home-treatable: rest, plenty of fluids, and simple pain-relief medicines for the fever and aches, with recovery over one to two weeks. Nothing over the counter shortens flu itself.
What home care cannot do: it cannot protect the people flu actually endangers. If you have asthma, COPD, diabetes, heart disease or a weakened immune system, antiviral treatment can matter and works best started early, which makes the first day or two the time to talk to a doctor, not day five. Breathlessness, chest pain, coughing blood, confusion or a fever that improves and then returns are signs to stop self-treating at any age.
Staying at home is the point of Mobi Doctor: you can see a licensed doctor over video, usually within 15 minutes, with no waiting room. If medication is the right answer, the prescription follows. Book a video consultation: the exact price is shown before you pay.
How Mobi Doctor works
- Book a time that suits you: open daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, exact price up front.
- Speak to a licensed doctor about flu: a private video call: you describe what you feel, the doctor asks what matters, and you agree the right plan together.
- Leave with your plan: everything agreed before you hang up: your plan, and a prescription to use at a pharmacy near you where medication is clinically right for you. If your doctor decides you need to be seen in person, you get a full refund.
No sign-up needed
Not sure it’s flu? Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Not sure this is the right page? Look up any symptom in the full symptom checker, or book and describe it to a doctor.
Frequently asked questions about flu
What is flu, and how do you catch it?
Flu is an infection of the nose, throat and lungs by influenza A or B viruses, which spread in droplets when an infected person coughs, sneezes or talks, and on hands and surfaces, where the virus survives about 24 hours. Symptoms start 1 to 3 days after exposure, and you can pass flu on from the day before you feel ill. The viruses change every year, so last winter's flu protects little against this winter's.
What are the symptoms of flu?
Flu arrives within hours: a fever of 38°C or more, chills, aching muscles and joints, exhaustion that keeps you in bed, a dry chesty cough, headache, sore throat, loss of appetite, and sometimes nausea, vomiting or diarrhoea. Feeling unable to get up is the hallmark. Breathlessness, chest pain, confusion, coughing blood, or a fever that returns after settling are the symptoms of a flu complication and need in-person care.
Can an online doctor prescribe antiviral flu medicine in Europe?
Yes, where clinically appropriate: typically for people in a higher-risk group, or with severe flu, seen within the first 48 hours of symptoms, when antivirals such as oseltamivir shorten the illness by about a day and reduce complications. The prescription is usable at a pharmacy near you, and a prescription is never issued without a consultation. Prescribing rules for flu antivirals vary between European countries, and the doctor says what is possible where you live.
How do I know if I have flu or just a cold?
Speed and severity. Flu hits within hours with fever, body aches and exhaustion that stops you working; a cold builds over one to two days, stays mostly in the nose and throat with sneezing and a runny nose, and leaves you functional. If you cannot get out of bed, treat it as flu; if you can go about your day feeling rough, it is more likely a cold. Fever is usual with flu.
Do antibiotics help flu?
No. Flu is caused by a virus, and antibiotics only work against bacteria; they are prescribed only if a bacterial complication such as pneumonia, a chest infection or an ear or sinus infection develops, which shows as a fever that settles and then returns, breathlessness, chest pain or coughing green sputum. Taking antibiotics for uncomplicated flu adds side effects and drives antibiotic resistance without shortening the illness by a single day.
Is it flu or COVID-19?
The symptoms overlap too much to tell reliably; both bring fever, cough, aches and exhaustion, and both circulate every winter. A rapid test from a pharmacy is the only dependable way to know, and it is worth doing: the result changes isolation advice and, for people in risk groups, which antiviral is used, since flu and COVID-19 have different ones. Tell the doctor any positive result; loss of smell points to COVID-19.
When am I no longer contagious with flu?
You are most infectious in the first 5 days of illness and can spread flu from the day before symptoms start; children and people with weakened immunity stay infectious longer. You are much less contagious once your fever has been gone for a full day without fever medicine and you are clearly improving. Staying home while feverish protects the people around you; a lingering dry cough alone does not mean you are still spreading flu.
Should I get the flu vaccine every year?
If you are in a risk group, pregnant, over 65 or living with a chronic condition, or you are a health worker or carer, yes: annual vaccination is the most effective protection against flu, and the vaccine is updated each season, so last year's dose does not cover this winter. Autumn is the time, protection takes about two weeks to build, and in many European countries a pharmacy gives it; the vaccine cannot cause flu.
How long does flu last?
Flu typically lasts about a week: the fever and aches are worst for the first 3 to 5 days, then lift, while the cough and tiredness often linger for one to two weeks longer, and full energy can take three weeks to return. Antivirals started within 48 hours shorten it by about a day. Flu that has not begun to improve after a week, or that worsens after improving, is reassessed for a complication.
How do I look after someone with flu at home?
Keep someone with flu resting and drinking enough that their urine stays pale, control the fever and aches with paracetamol or ibuprofen, offer light food, ventilate the room, wash hands after contact, and keep vulnerable household members at a distance in the first days. Watch for the escalation signs: breathlessness, confusion or drowsiness, chest pain, passing very little urine, or getting worse after improving, which need urgent care rather than more waiting.
How can I prevent flu?
Have the flu vaccine every autumn if you are in a risk group, pregnant or in contact with vulnerable people, wash hands often, avoid touching your face, keep distance from people with flu in their first days, ventilate rooms, and stay home when you are ill yourself. People at high risk who have been in close contact with flu can be offered preventive antivirals within 48 hours; they are no substitute for the vaccine.
Is flu more serious in pregnancy, over 65 or with a long-term condition?
Yes. Pregnant women, people over 65, and those with asthma, COPD, heart, kidney or liver disease, diabetes, a weakened immune system or severe obesity are far more likely to develop pneumonia and need hospital, which is why they are offered the vaccine each autumn and antivirals within 48 hours of flu symptoms, and why they should get medical advice the same day rather than waiting. Flu in pregnancy also raises the risk of premature birth.
Is it flu, pneumonia or something else?
Flu is sudden fever, aches and exhaustion that improve within a week. Pneumonia brings breathlessness, chest pain on breathing, a fast pulse, coughing rusty or green sputum, and often a fever returning after improvement: in-person care without delay. A cold is milder and nasal; COVID-19 and RSV mimic flu and are told apart by a test; glandular fever lasts weeks with swollen glands; meningitis adds a stiff neck or non-fading rash: 112.
- Influenza (seasonal) fact sheet, WHO, World Health Organization, 2023.
- Seasonal influenza, ECDC, European Centre for Disease Prevention and Control, 2024.
- Antimicrobial resistance fact sheet, WHO, World Health Organization, 2023.
- Tamiflu (oseltamivir): European public assessment report, EMA, European Medicines Agency, 2002 (updated).
- Factsheet about seasonal influenza, ECDC, European Centre for Disease Prevention and Control, accessed August 2026.
- Flu, NHS, National Health Service (UK), reviewed February 2026.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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