How do flu and a common cold differ, and when is treatment needed?
Flu often starts more abruptly with fatigue, body aches or fever, while a runny nose and sneezing are more typical of a cold. Symptoms overlap with other infections, including COVID-19, so they cannot confirm the diagnosis. Higher-risk patients may need early treatment.
Details
Testing depends on the situation
Not every respiratory illness needs testing, but a result may affect treatment or infection-control decisions. Tell the clinician when symptoms began, whether you are pregnant, and about chronic conditions and medicines. Lack of fever does not exclude influenza.
Antiviral treatment
Antivirals generally work best when started early, preferably within two days. Passing that point does not remove possible benefit in severe illness, hospitalised patients or higher-risk groups. Treatment is not automatic for every person; a clinician decides when it is appropriate. Antibiotics do not treat the influenza virus.
Concerning symptoms
Breathlessness, chest pain, confusion or significant dehydration requires urgent help. Rest, take fluids appropriate for your health and reduce contact with others while ill. Seek assessment if symptoms worsen after an initial improvement rather than assuming it is simply a longer cold.
Related reading: Who should consider a flu vaccine, and when should it be given?.