Every year, across the world, there are about 3 – 5 million cases of severe flu, and between 290,000 and 650,000 flu-related deaths.1 In the 2022-23 winter in England, they have estimated about 15,000 flu-related deaths (in all ages) with nearly 50,000 people taken in to hospital with confirmed flu.2
People most at risk of getting flu (and the complications) are those 65 years and older, young children especially under 5, pregnant women, and people with pre-existing health conditions.1,3
Most people who get the flu recover after a few days, some a few weeks; however, some children can develop complications.4
Mild complications
Mild flu complications can include sinus, ear or chest infections.
Sinus infections is an infection in the sinuses – spaces inside the head around the nose; and happens when flu spreads upwards in the spaces near the cheekbones and behind the forehead.5,6If your child complains of a blocked nose that hurts, has tenderness around the cheeks, eyes and forehead and the pain gets worse when they make sudden movements it could be sinusitis.5,6
If they have an ear infection, children may complain of not being able to hear properly, gunk may come from the ear, it might feel painful and stretched inside with itching, and there may be a change in how the skin looks around the ear.7 They might pull at their ears, not react to some sounds, lose their balance, or even change their mood.7
A chest infection may follow the flu – this can be seen as your child has a chesty cough, they cough up slimy mucus, and they might complain of pain in their chest.8
If you suspect any of these, you can talk to your local pharmacy for things you can use at home; or call your GPs or 111 for further advice.
Serious complications
These can include pneumonia (an infection in the lungs); inflammation (or swelling) of the heart, brain or muscle tissues; and it can cause multi-organ failure and sepsis.4
Pneumonia is serious lung infection with inflammation (this is how the body can respond to infection and includes swelling, heat and redness depending where it is).4,10 Signs can be sudden and it can look like the flu, but they can get suddenly worse over a couple of days; pneumonia can be life-threatening and cause chest pain, wheezing noises when they breathe, or grunting noises in babies.4,10 If you think your child may be developing pneumonia, call your GP surgery or 111 for further advice.
Sepsis is life-threatening; it is a way the body can respond to infection; it can be hard to spot.11 Some warning signs of sepsis in babies include blue, grey, or blotchy skin, a rash that does not fade when you put pressure on it (people use a glass so they can see if it fades or not), grunting noises, struggling to breathe (and sucking in their belly), not wanting to feed, dry nappies, and/or a high pitched cry that doesn’t sound like their normal cry.11 Trust your instincts – with sepsis it is better to be safe – if you suspect sepsis, call 999 or go to A&E.
Children with existing medical conditions
Children who have long-term (or chronic) medical conditions (these include diseases such as diabetes, chronic lung disease, blood disorders, heart disease, kidney disease, liver disorders, metabolic disorders) or children who are taking certain medications, are known to be more at risk of getting serious flu complications.9
If your child has asthma, they may be more likely to have asthma attacks while they have the flu.4
Flu treatment in hospitals
If your child gets very poorly and develops complications of flu, they may have to go to hospital and get more help. They may get a medicine group called ‘antivirals’; one that can, if started early enough, prevent some of the serious complications.12
Learn why it is important to get your child vaccinated against flu.
GB-68057 | August 2025
