flu risks and benefits for patients

Overview

Flu (short for influenza) is a common viral infection of the nose, throat, and lungs. It spreads easily from person to person, especially in autumn and winter. For most people, flu is an unpleasant few days of fever, aches, and tiredness. For others, it can lead to more serious illness — which is why it's important to understand your personal risks and the benefits of simple protections like vaccination.

Yes. Flu is one of the most common infections in the world. Millions of people catch it every year, usually during the winter months.

Anyone can get the flu, but some people are much more likely to become seriously ill: young children, adults aged 65 and older, pregnant women, and people with long-term conditions such as asthma, diabetes, heart disease, or a weakened immune system.

Symptoms

Common symptoms

• Fever or chills
• Cough, often dry and persistent
• Sore throat
• Runny or stuffy nose
• Muscle and body aches
• Headache
• Feeling very tired or weak
• Loss of appetite

Symptoms in children

• High fever
• Irritability, fussiness, or clinginess
• Being much sleepier than usual
• Vomiting or diarrhea (more common in children than adults)
• Cough and a runny or blocked nose
• Refusing to eat or drink

Symptoms in older adults

• Fever (though some older adults have no fever or only a very low one)
• Confusion, dizziness, or being less alert than usual
• Severe tiredness and weakness
• Worsening of existing health conditions, such as heart or lung disease
• Trouble breathing or wheezing
• Loss of appetite and reduced mobility

Causes

Main causes

• Flu is caused by influenza viruses. The two main types — A and B — change over time, which is why people can catch flu more than once and why the vaccine is updated every year.
• The virus spreads through tiny droplets in the air when an infected person coughs, sneezes, or talks. You can breathe those droplets in, or touch surfaces that have the virus on them and then touch your eyes, nose, or mouth.

Risk factors

• Being 65 years of age or older
• Being under 5 years old
• Being pregnant or recently pregnant
• Having long-term conditions such as asthma, COPD, diabetes, heart disease, kidney disease, or a weakened immune system
• Living in a care home or other shared facility
• Having a very high body mass index (BMI)

When to see a doctor

See a doctor urgently if:

• You have a long-term health condition and your flu symptoms are making you feel noticeably worse — contact your GP surgery or local health service for same-day advice.
• You are pregnant and develop flu symptoms.
• Your child is under 5, seems very unwell, or is not drinking or feeding normally.
• You are an older adult and feel extremely weak, confused, or unable to manage daily tasks.
• Your fever lasts more than a few days or comes back after improving.

Book a routine appointment if:

• You are in a higher-risk group and think you have the flu — early care can reduce your chance of complications.
• Your symptoms last more than about a week without improving.
• You aren't sure whether you need an appointment or which precautions to take.

Diagnosis

In most cases, a doctor can diagnose flu simply by asking about your symptoms and knowing whether flu is going around your community. Tests are only needed when the result would change treatment or when the illness is severe.

Tests that may be done

• A gentle swab from the back of your nose or throat — this is checked for the flu virus (results may take a few hours or days).
• Rapid flu tests available in some clinics, which give results in about 15 to 20 minutes.
• Blood tests or a chest X-ray, but only if the doctor is worried about complications such as pneumonia.

What to expect at your appointment

A flu consultation is usually quick. The doctor or nurse will ask when your symptoms started, how you're feeling, and whether you have any health conditions. They may listen to your chest with a stethoscope and check your temperature. You don't need any special preparation for this visit.

Treatment

There is no 'cure' for flu — treatment is about supporting your immune system while it clears the virus. For most people, that means resting at home. Some higher-risk patients may be offered antiviral medicines, which can shorten the illness and reduce its severity, especially if started early on.

Self-care at home

• Rest as much as possible, and stay home from work, school, or social events until you've had no fever for at least 24 hours (without using fever-reducing medicine).
• Drink plenty of fluids — water, herbal tea, or warm soup — to prevent dehydration.
• Use a cool cloth on your forehead or a fan on a low setting if fever makes you uncomfortable.
• Sleep propped up with an extra pillow if coughing or a blocked nose keeps you awake.
• Wash your hands regularly, use tissues for coughs and sneezes, and dispose of used tissues safely so you don't spread the virus.

Medical treatments

Doctors can prescribe antiviral treatment for certain people — for example, those in high-risk groups or people with severe illness. These medicines are not a cure, but they can reduce symptoms and shorten the illness if taken early. Over-the-counter pain and fever relief may also help with aches and discomfort — talk to your pharmacist about what is safe for you or your child, and never give medicines containing aspirin to anyone under 16.

Living with this condition

Flu can really knock you off your feet. Plan for a few days of rest: cancel non-essential activities, let work or school know, and ask family or friends to help with groceries or childcare. You're usually contagious for up to about a week, so it's kind to stay away from others, especially people at high risk.

Lifestyle tips

• Take time off work or school — returning too early makes recovery slower and spreads the virus.
• Avoid strenuous exercise until your symptoms have fully settled — a gentle stretch or short walk is enough.
• Keep a simple routine — regular meals, fresh air in the room, and a normal sleep pattern help your body recover.
• Avoid smoking or vaping, as this can make respiratory symptoms worse.

Diet and exercise

While you're ill, focus on liquids and light foods such as soups, toast, rice, bananas, or applesauce. There's no need to force yourself to eat, but try to keep drinking. Once you feel better, return gradually to physical activity — start with a 10-minute walk and build up at your own pace.

Mental health and emotional wellbeing

Being ill and stuck at home can feel lonely and frustrating. It's normal to feel low, anxious, or annoyed about missing out. Stay connected with phone or video calls, do relaxing things like listening to music or reading, and remember that low mood usually lifts as you recover. If you feel very low, hopeless, or have thoughts of harming yourself, reach out for help right away — contact a mental health crisis line, your doctor, or your nearest emergency department.

Prevention

No prevention is 100% guaranteed, but you can greatly reduce your chances of catching flu and spreading it to others. Combining yearly vaccination with simple hygiene habits is the most effective approach we have.

Vaccines

The flu vaccine is recommended every year for people at higher risk, including older adults, people with long-term conditions, pregnant women, and children in certain age groups. Because flu viruses change, the vaccine is updated each year, so it's important to get it annually. It is usually available at GP surgeries and pharmacies — ask your local health service how to book. The vaccine cannot give you flu, though you may feel mild arm soreness or a slight fever for a day or two afterwards.

Screening programmes

There is no routine screening test for flu. Prevention relies on vaccination and hygiene: wash your hands often with soap and water, use hand gel when soap isn't available, cover your mouth and nose with a tissue when coughing or sneezing, and stay home when you're unwell. If you're in a high-risk group, you may also want to avoid large crowds during flu season.

Complications

If left untreated

• Pneumonia — an infection in one or both lungs
• Bronchitis or worsening of chronic chest conditions
• Ear infections, especially in children
• Severe dehydration from fever and poor fluid intake
• Worsening of long-term conditions such as diabetes, asthma, or heart failure
• In rare cases, inflammation of the heart (myocarditis) or brain (encephalitis)

Long-term outlook

The vast majority of people — including those at higher risk — recover fully from flu, usually within one to two weeks. Even when complications do occur, most are treatable with good medical care, especially when help is sought early. Vaccination, rest, and reaching out for support when you need it give you the best chance of a safe and smooth recovery.

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