Influenza (seasonal) - World Health Organization (WHO) Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world It is characterized by a sudden onset of fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and a runny nose The cough can be severe and can last two or more weeks
Pneumonia - Symptoms and causes - Mayo Clinic Symptoms The signs and symptoms of pneumonia vary from mild to severe, depending on factors such as the type of germ causing the infection, and your age and overall health Mild signs and symptoms often are similar to those of a cold or flu, but they last longer Signs and symptoms of pneumonia may include: Chest pain when you breathe or cough
Influenza: A (H5N1) - World Health Organization (WHO) H5N1 is one of several influenza viruses that causes a highly infectious respiratory disease in birds called avian influenza (or "bird flu") Infections in mammals, including humans, have also been documented H5N1 influenza virus infection can cause a range of diseases in humans, from mild to severe and in some cases, it can even be fatal Symptoms reported have primarily been respiratory
Hantavirus pulmonary syndrome - Symptoms causes - Mayo Clinic The symptoms of hantavirus pulmonary syndrome can worsen suddenly and may quickly become life-threatening If you have flu-like symptoms that progressively worsen over a few days, see your healthcare professional Get immediate medical care if you have trouble breathing
Flu symptoms: Should I see my doctor? - Mayo Clinic I think I have the flu, also called influenza Should I see my doctor? Call your healthcare professional if you think you have the flu and you or someone you're caring for is at high risk of serious flu illness, or flu-related complications Unlike a cold, the flu tends to come on suddenly and makes you feel much worse than a cold
Coronavirus disease (COVID-19): Similarities and differences between . . . COVID-19 and seasonal influenza (flu) are respiratory infections caused by two different viruses While some of the signs, symptoms and population groups at risk of severe complications are similar, there are some important differences This questions and answers page will help you know the facts about both COVID-19 and influenza so you can make more informed decisions about your health