Medically reviewed by Dr. Ponlawat Pitsuwan, Physician, Takecare Clinic Phuket. Last reviewed: September 2026.
Flu circulates in Thailand year round, and I often see travellers who caught it on the flight or in a crowded tour group. For healthy adults, rest and fluids are usually enough, but for older people and those with long-term conditions, early antiviral treatment can make a real difference.
Flu reaches our clinics in two ways. Some travellers catch it in a crowded departure lounge or on a long-haul flight and wake on day two or three of the holiday with a fever, a pounding head and legs too achy for the beach. Others pick it up locally, because influenza circulates in Thailand all year and tends to rise in the rainy months. Heat, air conditioning, late nights and alcohol make the exhaustion feel far worse than it would at home.
What flu is, and why it hits so hard
Influenza is a respiratory infection caused by influenza A and B viruses. Influenza A subtypes such as H1N1 and H3N2 change slightly each year, which is why seasonal epidemics keep returning and the vaccine is reformulated annually. It spreads in droplets and on hands, and starts abruptly one to four days after exposure with fever, chills, muscle pain, headache and a dry cough. Most healthy adults recover within a week. The worry is complications: pneumonia, worsening asthma or heart disease, and ear or sinus infections.
Flu, COVID-19, a cold or dengue?
In the tropics the first question is not simply whether this is flu. Dengue, spread by day-biting mosquitoes and common in Phuket, can look identical for the first few days, and COVID-19 overlaps heavily too.
| Illness | Onset | Typical clues | Test we may use |
|---|---|---|---|
| Influenza | Sudden, over hours | High fever, chills, aches, dry cough | Rapid influenza A and B swab |
| COVID-19 | Gradual or sudden | Sore throat, cough, fatigue | COVID-19 antigen swab |
| Common cold | Gradual | Runny nose, sneezing, little fever | Usually none |
| Dengue | Sudden high fever | Pain behind the eyes, rash, little cough | NS1 antigen (days 1-5), blood count |
Because dengue can turn dangerous with the wrong painkillers, anyone with a new fever in Phuket should take paracetamol, not ibuprofen or aspirin, until dengue has been ruled out.
How we assess and treat flu
The doctor checks your temperature, pulse, breathing rate and oxygen saturation, listens to your chest and asks about asthma, diabetes, pregnancy and regular medicines. A nose swab for influenza A and B gives a result within minutes, often alongside a COVID-19 antigen test, and if dengue is possible an NS1 blood test and blood count come back the same day from our on-site laboratory. Rapid swabs miss some true infections, so when your symptoms fit, the doctor may still treat on clinical grounds.
Oseltamivir: who really benefits
Oseltamivir is an antiviral tablet that stops new virus particles escaping infected cells. The adult course is 75 mg twice daily for five days. It works best within 48 hours of the first symptoms and, in healthy adults, shortens the illness modestly, often by about a day. For higher-risk people it matters more and is worth starting even after 48 hours: adults over 65, pregnant women, and people with asthma, chronic heart, lung, kidney or liver disease, diabetes, weakened immunity or significant obesity. Taking it with food reduces nausea, the commonest side effect. Antibiotics do nothing for the virus itself; we prescribe them only for a bacterial complication such as pneumonia or a middle ear infection.
Looking after yourself in a hotel room
Rest properly, because pushing through a boat trip tends to prolong flu. Drink enough to keep your urine pale, using an oral rehydration solution if you are sweating heavily or not eating. Adults can usually take 1 g of paracetamol up to four times in 24 hours, at least four hours apart, with lower doses under 50 kg or with liver disease. Skip alcohol and stay off the scooter, since fever slows reactions and flu makes you light-headed. Keep away from others, particularly older or pregnant companions, until you have been fever-free for 24 hours without paracetamol.
Flu usually peaks around days two to four, which can collide with an island tour or the flight home. If you fly within a few days, see a doctor early so an antiviral can start inside the 48-hour window and you have paperwork for your insurer.
When to see a doctor
A fever that improves and then returns, or a cough that turns productive with pain on breathing in, can mean a secondary bacterial pneumonia. Breathlessness at rest, chest pain, confusion, blue lips or being unable to keep fluids down are not symptoms to watch from the hotel bed.
Prevention and early detection
The annual flu vaccine is the most useful protection, especially for people over 65, pregnant women and anyone with chronic heart, lung or kidney disease or diabetes. It takes about two weeks to work, and because the strains change every year, last year’s injection may not cover this season. See our page on vaccinations in Phuket, and ask us on WhatsApp whether the flu vaccine is in stock today. Handwashing and a mask in crowded airports also help. Early detection is about speed: higher-risk travellers should get tested as soon as a sudden fever appears, and high-risk contacts of someone with flu may be offered preventive oseltamivir.
Getting flu care from Takecare Clinic
All three clinics are open 24 hours a day with no appointment needed. Walk in at our Bangtao (Cherngtalay) clinic, the Kata-Karon clinic or the Patong clinic, and you will usually be seen within minutes. If you would rather not sit in a waiting room while feverish, message us on WhatsApp or call +66 81 718 9080 to arrange a doctor hotel visit in Phuket, day or night. We confirm the price on WhatsApp before your visit, bill most travel insurers directly, and provide medical reports, receipts and itemised invoices for claims.
Related services and treatments
Flu rarely travels alone. A throat that stays raw is covered under sore throat treatment, swollen tonsils with white patches under tonsillitis treatment, and a lingering cough under bronchitis treatment. If your chest tightens with every virus, read about asthma care in Phuket; a positive coronavirus swab leads to COVID-19 treatment. Blocked ears after a flight may need ear infection treatment, a streaming nose without fever may need allergy treatment, and an unexplained temperature is covered under fever treatment. See also our walk-in doctor in Phuket service and all the conditions we treat.
Summary
Flu is a sudden, whole-body viral illness that most healthy adults get over in about a week. Oseltamivir helps most within 48 hours and matters most for older, pregnant or chronically ill people. In Phuket, treat any new fever with paracetamol until dengue is excluded, and if you are higher risk, breathless or facing a flight home, get assessed early.
“If you are in a higher-risk group, see a doctor within 48 hours of flu symptoms starting. That is when antiviral treatment works best.”
Dr. Ponlawat Pitsuwan, Physician, Takecare Clinic Phuket
Frequently asked questions
Is it worth seeing a doctor for flu if I am young and healthy?
Often it is optional, but it is worthwhile if you are unsure it is flu, have a flight booked soon, or are getting worse. A test separates flu from COVID-19 and dengue, which changes what you should take for the fever, and within 48 hours an antiviral is still possible.
Will my travel insurance cover a flu consultation?
Most travel policies cover illness abroad, including flu, but terms and excesses vary, so check whether you must call your insurer first. We bill most travel insurers directly, and otherwise give you a medical report, receipt and itemised invoice to claim. We confirm the price on WhatsApp before your visit.
How fast will I know whether it is flu?
The rapid influenza swab gives a result within minutes during your visit, and a COVID-19 antigen test can be run at the same time. If dengue is possible, the NS1 test and blood count come back the same day from our on-site laboratory. Most walk-in visits are finished in under 30 minutes.
Do I need to book an appointment for flu symptoms?
No. All three clinics accept walk-ins 24 hours a day, and patients are usually seen within minutes. If you would rather not wait near other patients while infectious, send a WhatsApp message first so we can prepare for your arrival or send a doctor to you instead.
Can a doctor come to my hotel if I am too ill to leave the room?
Yes. Our doctors visit hotels, villas and condos anywhere in Phuket, day or night. They check your temperature, oxygen level and chest, take a flu and COVID-19 swab, and arrange the medicines you need. A room visit also stops you spreading the virus to other guests.
Can I still fly home if I have flu?
Avoid flying while you have a fever, both for comfort and because airlines can refuse passengers who look acutely unwell. Many people are fit to travel once they have been fever-free for 24 hours without medicine. If your date is close, see a doctor early and ask about a medical report for your insurer or airline.
Sources
The NHS covers symptoms and home care on its flu condition page. The CDC sets out who should receive antivirals in its guidance on treating flu. The World Health Organization explains seasonal epidemics and vaccination in its seasonal influenza fact sheet.
Influenza, flu, seasonal influenza, influenza A, influenza B, H1N1, H3N2, oseltamivir, antiviral treatment, paracetamol, rapid influenza antigen test, COVID-19 antigen test, pulse oximetry, dengue NS1 antigen, complete blood count, pneumonia, flu vaccine, WHO, CDC, NHS, Bangtao, Cherngtalay, Kata, Karon, Patong, Takecare Clinic Phuket, Dr. Ponlawat Pitsuwan
This page is general health information and not a substitute for a medical consultation.