Influenza: self-care and warning signs

Published: 2026-10-26Last reviewed: 2026-10-268-minute readReviewed by: Dr. Gabriel Fernando Peñarrieta Pozo

Key points

✓ Influenza often begins suddenly with fever or chills, cough, muscle aches, headache, and fatigue, although not everyone has a fever.
✓ Annual vaccination is the main preventive measure, together with hand hygiene, covering coughs, and improving indoor ventilation.
✓ People at higher risk of complications should seek medical advice early when compatible symptoms develop.

Symptoms often begin suddenly and may include fever or feeling feverish, chills, cough, sore throat, congestion, muscle aches, headache, and fatigue.
Some people, especially children, may also have vomiting or diarrhea; not everyone with influenza has a fever.
A cold, influenza, and other respiratory infections can look similar. Symptoms alone do not always identify the responsible virus.
Most people improve within several days, but cough and fatigue may last longer, and some people develop complications such as pneumonia.

Rest, drink fluids regularly, and monitor temperature and overall condition. Use fever or pain medicines only according to professional advice or safe instructions for your age and health condition.
Stay home while you have a fever or feel unwell, avoid close contact with other people, and improve indoor ventilation when possible.
Cover coughs and sneezes with your elbow or a tissue, discard the tissue, and wash your hands frequently.
If you need to be near other people while recovering, a well-fitting mask can help reduce the spread of respiratory viruses.

Seek advice promptly during pregnancy, at age 65 or older, for a child younger than 5—especially younger than 2—or when a chronic condition is present.
Risk is also higher with asthma or another lung condition, heart disease, diabetes, kidney or liver disease, neurologic disorders, or a weakened immune system.
Antiviral medicines require medical assessment and prescribing. They may be particularly important for higher-risk people, and their benefit is usually greater when started early.
Arrange an assessment when symptoms are severe, do not improve as expected, return after improvement, or worsen an existing medical condition.

Influenza vaccines are updated periodically and are generally recommended each year; a clinician can advise on timing according to age, medical history, and local availability.
Vaccination is especially important for people at higher risk of complications and those who care for them.
Vaccination does not treat an infection that has already started, but it lowers the risk of illness and severe disease.
When seeking care, explain when symptoms began, existing conditions, pregnancy, regular medicines, and recent changes in overall condition.

Difficulty breathing, fast breathing, bluish lips, or ribs pulling in with each breath
Persistent pain or pressure in the chest or abdomen
Confusion, difficulty waking, seizures, fainting, or severe weakness
Signs of dehydration, such as not urinating, a very dry mouth, or inability to drink
Fever or cough that improves and then returns or worsens, or worsening of a chronic condition

Do not use antibiotics on your own: they do not treat the influenza virus.
Do not give aspirin to children or teenagers with a viral infection unless a clinician specifically prescribes it.
Do not share antiviral medicines or other treatments, and do not start them without medical assessment.
Do not delay medical advice if you are at higher risk or develop a warning sign.

If you have symptoms, risk factors, or questions about your situation, arrange a professional medical assessment.