In short
Influenza tends to hit harder and faster than a common cold, and antiviral treatment works best when started early. Here's how to spot the difference and who needs closer attention.
Emergency if: Difficulty breathing, chest pain or pressure that does not go away, confusion, being hard to wake, a seizure, or fever or cough that improve and then come back worse: go to an emergency department now, or call emergency services now if breathing is very difficult.
On this page
01
Flu vs. Cold
Influenza is caused by influenza viruses and tends to start abruptly, with fever, chills, body aches, and exhaustion arriving within hours. A common cold, caused by different viruses such as rhinoviruses, usually builds more gradually and centers on a runny nose and mild sore throat with less severe fatigue. The abruptness and intensity of onset is often the clearest clue that it's flu rather than a cold.
02
How It Spreads and Who's at Higher Risk
Flu spreads through respiratory droplets from coughing, sneezing, or talking, and through contaminated surfaces. Young children, adults 65 and older, pregnant women, and people with chronic conditions like asthma, diabetes, or heart disease are more likely to develop complications such as pneumonia, so symptoms in these groups deserve prompt medical attention rather than a wait-and-see approach.
03
Symptoms
Typical flu symptoms include fever, chills, muscle aches, headache, dry cough, sore throat, and fatigue that can last a week or more, with tiredness sometimes lingering afterward. Emergency warning signs include difficulty breathing or shortness of breath, chest pain or pressure that does not go away, persistent dizziness or confusion, being hard to wake, seizures, or fever or cough that improve and then return or get worse: go to an emergency department now, or call emergency services if breathing is very difficult. A long-term condition that is getting worse needs a doctor today.
05
Treatment and Prevention
Most healthy people recover with rest, fluids, and symptom relief alone. An annual flu vaccine remains the most effective tool for preventing infection or reducing its severity, and is especially recommended for those at higher risk of complications. A primary care doctor can advise on antiviral treatment and vaccine timing each season.
How urgent is it?
Emergency — act now
Difficulty breathing, chest pain or pressure that does not go away, confusion, being hard to wake, a seizure, or fever or cough that improve and then come back worse: go to an emergency department now, or call emergency services now if breathing is very difficult.
Same-day — call promptly
Flu symptoms and you are 65 or over, pregnant or recently gave birth, have a long-term condition such as diabetes, asthma or heart disease, have weak immunity, or a long-term condition is getting worse: see a doctor today. Antiviral medicine works best within about 48 hours.
Routine — see a doctor
Mild flu in an otherwise healthy adult: rest, fluids and symptom relief at home, and see a doctor if you are not improving after a week.
Sources
- Flu - MedlinePlusmedlineplus.gov
- Influenza (Seasonal) - WHO Fact Sheetwho.int
- Flu — NHSnhs.uk
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