During autumn and winter, in addition to influenza A and B viruses, the presence of other pathogens is recorded, including SARS-CoV-2, responsible for Covid-19, respiratory syncytial virus (RSV) and rhinoviruses, among the main causes of colds. Simultaneous circulation can lead to an increase in respiratory infections even before the traditional flu peak, which in Italy is generally concentrated between December and February. The different diseases have common characteristics, but can be distinguished by intensity of symptoms, mode of onset and duration.
Seasonal flu generally appears suddenly, with fever often above 38 degrees, chills, headache and muscle or joint pain. The most frequent ailments also include cough, sore throat, fatigue and nasal congestion. In children, nausea, vomiting and diarrhea may appear, while in the elderly the increase in temperature may be less evident. As Pregliasco always reminds us, the typical flu picture includes an abrupt onset, high fever, at least one respiratory symptom and a general disorder. Not all people with the flu, however, necessarily develop a fever.
The common cold mainly affects the upper respiratory tract and tends to cause less intense symptoms than the flu. The most characteristic manifestations are runny or stuffy nose, frequent sneezing, throat irritation and cough. Mild malaise, headache and a modest feeling of fatigue may also appear. High fever and particularly intense muscle pain are less common in adults. Unlike the flu, disorders often develop gradually, without a sudden worsening of the general condition.
The distinction between flu and Covid cannot be established with certainty by observing the symptoms alone. Antigenic or molecular tests can be used to detect SARS-CoV-2, while specific tests allow the detection of influenza viruses. Combined tests capable of simultaneously searching for multiple pathogens are also available. A negative result, especially in the early stages of the infection, does not always exclude contagion. The use of tests must be evaluated based on the symptoms, risk conditions and the doctor's indications, especially when a timely diagnosis can guide treatment.
Flu, Covid and colds are transmitted mainly through respiratory particles emitted by talking, coughing, sneezing or breathing. Closed, crowded and poorly ventilated environments favor the spread. For influenza the incubation generally lasts from one to four days, while for Covid it can be longer. An infected person can be contagious even before symptoms appear. In colds, however, transmission is particularly frequent in the first days of the illness. For all three cases, limiting contact during the symptomatic phase helps protect others.
When symptoms are mild, treatment mainly consists of rest, regular fluid intake and control of discomfort. Medicines such as paracetamol and ibuprofen can be used, when appropriate, to relieve fever and pain, respecting dosages and contraindications. Antibiotics do not act on viruses and should only be prescribed in the presence of bacterial infections. For flu and Covid there are also specific antiviral treatments, intended especially for selected patients and to be started promptly upon medical indication. Flu medicines are not interchangeable with those used for Covid.
It is advisable to contact your family doctor or pediatrician if the disorders persist, worsen or affect particularly vulnerable people. Prompt evaluation is also important when fever lasts several days or reappears after initial improvement. Difficulty breathing, persistent chest pain, sudden confusion, severe dehydration, or loss of consciousness may be signs that you need urgent care.
Vaccination represents one of the main protection measures against influenza and Covid, especially to reduce complications, hospitalizations and serious forms. For the 2026-2027 season, the flu vaccine is recommended in particular for those over 60, pregnant women, children aged six months to six years and people with certain pathologies. Protection generally develops within two weeks. However, there is no commonly used vaccine against colds. To limit the spread of viruses, hand washing, ventilation of rooms, respiratory hygiene and reducing contacts when you are sick remain essential.
