Flu: symptoms, causes and treatment in Luxembourg

The flu is a viral respiratory infection that circulates in Luxembourg every year during the cold season, roughly from November to March. It is recognised by how suddenly it strikes: high fever, muscle aches, exhaustion and chills often appear within hours, unlike a cold which builds up gradually. A GP (general practitioner) is the first point of contact to confirm the diagnosis, relieve symptoms and spot situations that need closer follow-up.

Flu, cold or Covid-19: telling them apart

Three respiratory infections circulate in winter, and their symptoms overlap enough to cause real confusion. A cold stays mostly in the nose and throat: runny nose, sneezing, sore throat, with little or no fever, building up gradually over two or three days. Flu, by contrast, hits the whole body at once: fever of 39-40°C, marked body aches, headache, exhaustion that can keep you in bed. Covid-19 shares some signs with flu — fever, fatigue, cough — but more often comes with a loss of taste or smell and can develop more slowly.

None of these three patterns can be told apart with certainty just by how you feel. If in doubt, especially when vulnerable people live in your household, a test done by your GP or at a pharmacy can distinguish these viruses and guide the precautions your household should take.

A seasonal illness, but not harmless for everyone

In an otherwise healthy adult, flu usually clears up within a week to ten days with rest, plenty of fluids and medication to ease fever and aches. The body simply needs time to fight off the virus.

The picture is different for certain groups, in whom flu can lead to complications, particularly pneumonia: infants and young children, people over 65, pregnant women, and anyone living with a chronic condition — heart or lung disease, diabetes, a weakened immune system. For these groups, seeing a doctor early is not overcaution but a genuine precaution, and closer follow-up throughout the illness is worthwhile.

When to see a doctor, when to call 112

A visit to your GP is worthwhile if fever stays above 39°C for more than three days, if symptoms worsen after an initial improvement, if a cough lingers beyond ten days, or if you belong to one of the at-risk groups mentioned above. A paediatrician follows the same logic for children, with extra vigilance under the age of two.

Some signs call for 112 without delay: difficulty breathing or breathlessness at rest, chest pain or tightness, sudden confusion, bluish lips or face, or a very high fever in an infant that will not come down with treatment.

Flu vaccination: a yearly choice worth discussing

The flu vaccine, offered every autumn in Luxembourg, lowers the risk of severe illness and hospitalisation, though it does not guarantee complete protection against infection. It is particularly recommended for people at risk of complications listed above, as well as healthcare workers and those living with vulnerable people. Because the vaccine composition is adjusted each year to match circulating strains, the decision is best made with your GP, who takes your health history into account.

Lingering fatigue after the fever is gone

Many people are surprised to still feel exhausted a week or two after their fever has cleared. This post-flu fatigue is normal: the immune system spends a great deal of energy fighting the infection, and the body needs time to recover even once the acute symptoms have passed. Going back to work or school too early, before fever has been gone for at least twenty-four hours, risks a relapse and extends the period during which you can pass the virus on to others.

There is no single rule for when it is safe to resume normal activity, but one simple benchmark works well: wait until you can get through a full day with no fever and no need to lie down. At work, letting colleagues know in advance, especially if they regularly see older or immunocompromised relatives outside the office, is a small courtesy that helps limit the spread of the virus through the workplace.

The care pathway in Luxembourg

In Luxembourg, no referral is required to see a GP or paediatrician for flu-like symptoms. Consultations, any tests and the flu vaccine are covered by the Caisse nationale de santé (CNS) under standard reimbursement conditions. You can find an available GP or paediatrician near you and book an appointment directly on Doctipro.