What are the symptoms of influenza?

Flu symptoms often arrive over a short time rather than building gradually. The illness may leave you exhausted and may cause sweating, chills, aching joints or discomfort behind the eyes. Some people also develop a runny nose, nausea, vomiting or diarrhoea, especially children. Symptoms can overlap with other respiratory infections, so the symptom pattern alone cannot confirm influenza.

A cough and tiredness may continue after fever improves. Children can become irritable or feed less, while older adults may have less obvious fever but marked weakness or confusion.

Rest, drink fluids regularly and consider simple foods if your appetite is low. Stay home while you feel unwell and reduce close contact with people who may become seriously ill. Record when symptoms began, your temperature if you check it, and any breathing changes. A GP Consultation or Telemedicine Consultation can help assess symptoms and whether testing or treatment is appropriate.

Seek advice before taking medicines if you are pregnant, caring for a young child, or have a long-term condition. Do not give children medicines intended for adults.

Arrange prompt medical advice for worsening symptoms, breathing difficulty, dehydration, persistent vomiting, severe weakness, chest pain, or confusion. Urgent help is needed for blue or grey lips, severe trouble breathing, fainting, or a child who is unusually difficult to wake. A high temperature can trigger Febrile Seizures in some children; seek emergency help if a seizure occurs.

Ask: Could these symptoms be influenza or another infection? Do I need an examination or test? Which fluids, rest measures or medicines are suitable for me? What changes should prompt urgent care?