As explained by therapist Alla Shelipova, technically both flu and COVID-19 fall under acute respiratory viral infections. However, they are typically distinguished due to differences in their course and the risk of serious complications. ### Common ARVI: Gradual Onset With a common cold, symptoms often do not appear suddenly but rather develop over one to two days. Initially, there may be a scratchy or sore throat, followed by a runny nose, nasal congestion, and cough. The temperature often remains low, and weakness and general malaise may occur. According to the doctor, it is the symptoms related to the nose and throat that often take center stage. Usually, the condition significantly improves after about a week.  ### Flu: Feeling Fine in the Morning, High Fever in a Few Hours The flu is characterized by a sudden onset. A person may feel completely fine in the morning, only to be knocked off their feet a few hours later. A typical picture includes high fever, chills, severe weakness, headache, and aches in muscles and joints. A runny nose may be absent, and the cough is often dry and painful. It is the sudden onset and pronounced deterioration of the general condition that can distinguish the flu from a regular seasonal cold. ### COVID-19 Can Mimic Both Infections COVID-19 is more complex: it can resemble either a mild cold or the flu, and sometimes it can occur with almost no symptoms. Symptoms may include fever, cough, weakness, sore throat, and runny nose. Changes or loss of taste and smell can also occur, but this is no longer a mandatory sign of COVID-19. Shortness of breath and a feeling of lack of air require special attention. Additionally, symptoms of different infections can overlap. It is also possible to be simultaneously infected with both the flu and coronavirus. Therefore, the presence of one virus does not exclude the other. If it is necessary to accurately identify the pathogen, laboratory diagnostics will be required — PCR or rapid tests for influenza A/B and SARS-CoV-2 antigens. ### When to Seek Help Without Delay Particular attention is required for high fever that does not respond well to antipyretics or lasts more than three days, shortness of breath, and difficulty breathing, as well as pain or heaviness in the chest. Worrisome symptoms also include confusion, pronounced lethargy, fainting, seizures, repeated vomiting, and signs of dehydration. Another serious signal is a sudden deterioration after a person has already started to feel better. In cases of severe or rapidly worsening symptoms, urgent medical assistance is necessary. ### If Improvement Takes Too Long A doctor's consultation is also needed in less acute situations if the condition does not improve or begins to worsen. This should be especially taken seriously by elderly people, pregnant women, small children, and patients with chronic diseases. The doctor can assess the condition of the respiratory system and, if necessary, prescribe additional tests, including a complete blood count and C-reactive protein. At the same time, antibiotics do not work against viruses. They may be required for certain bacterial complications and should be used as prescribed by a doctor. ### Prevention Remains the Simplest Protection During the season of respiratory infections, familiar measures help: regular hand washing, ventilating rooms, resting at the first signs of malaise, and reasonable use of masks in crowded places. Vaccination against the flu is also of particular importance. It does not guarantee that a person will not get sick at all, but it is primarily intended to reduce the risk of severe illness and complications. The main thing is not to try to diagnose yourself solely based on a set of symptoms. Cold, flu, and COVID-19 can be very similar, so in cases of severe, unusual, or prolonged illness, it is better to consult a doctor.
