When your child is unwell, it can be worrying and difficult to know when to seek medical help.
Understanding common childhood illnesses, how long they typically last, and the signs of more serious conditions can help parents manage their child’s health with confidence.
At Kent Family Medical, we understand how important it is for parents to have quick access to professional medical advice.
If you cannot find an available appointment online then please do call us – we will always try to be as flexible as possible.
If your child is known to have a weakened immune system due to an underlying medical condition or treatment that they are receiving, then it is important to seek help quickly if they become unwell.
Note: This article is for informational purposes only and is not a substitute for medical advice. If you have concerns, consult a doctor.
The Most Common Childhood Illnesses
Viral infections, particularly during autumn and winter, are very common in children. Most coughs, colds, and sore throats are caused by viruses, meaning antibiotics are not needed.
However, monitoring symptoms and duration is important to identify more serious conditions.
Below is a guide to the most common illnesses, what to look out for, and when to seek help.
While most of these conditions resolve on their own, some require medical attention.
1. Ear Infections
Ear infections are one of the most common childhood illnesses, often occurring after a cold or upper respiratory infection.
Symptoms: Ear pain, trouble hearing, fever, irritability, and fluid drainage from the ear.
Treatment: Pain relief with paracetamol or ibuprofen, and encourage fluid intake.
Expected duration: 3 days (seek advice if lasting longer than this)
Worrying symptoms / when to seek help:
- Pain in both ears, discharge from one or both ears, swelling around the ear, fever, hearing loss, something stuck in the ear.
- If your child is struggling with their breathing, using extra muscles to help them breathe, becoming tired / floppy
- Drinking less and passing less urine than normal
More information can be found here: www.nhs.uk/conditions/earache/
2. Stomach Bugs (Gastroenteritis)
Caused by viral or bacterial infections, stomach bugs lead to vomiting and diarrhoea.
Symptoms: Nausea, vomiting, diarrhoea, abdominal pain, fever, dehydration.
Treatment: Encourage fluids (oral rehydration solutions) and bland foods when tolerated.
When to Seek Medical Help: If vomiting or diarrhoea persists for more than 2-3 days, dehydration occurs, or there is blood in the stool.
3. Hand, Foot, and Mouth Disease
A common viral illness that spreads easily among young children.
Symptoms: Fever, sore throat, blisters on the hands, feet, and inside the mouth, irritability.
Treatment: Pain relief with paracetamol, hydration, and soft foods. The illness typically resolves on its own within a week.
When to Seek Medical Help: If your child is unable to swallow fluids, has a high fever, or appears extremely unwell.
4. Chickenpox
A highly contagious viral infection that commonly affects children.
Symptoms: Itchy rash with red spots that turn into blisters, fever, fatigue, and loss of appetite.
Treatment: cool baths, antihistamines for itching, and paracetamol for fever.
Avoid ibuprofen as it may increase the risk of complications, including sepsis.
When to Seek Medical Help: If your child develops breathing difficulties, the rash becomes infected, or they are excessively drowsy.
Other Illnesses To Be Aware Of
1. Viral Sore Throat
- Expected Duration: Up to 2 weeks (seek help if not improved after 1 week)
When to Seek Medical Advice:
- Persistent high fever
- Pus or white patches on the tonsils
- Sore throat without a cough
- Difficulty swallowing or drooling
- Breathing difficulties
Call 999 if your child:
- Cannot swallow or is drooling
- Has severe symptoms that worsen rapidly
- Has stridor (a high-pitched sound when breathing)
🔗 More information on sore throats
2. Common Cold
- Expected Duration: 10–14 days
When to Seek Medical Advice:
- Severe breathing difficulties
- Persistent high fever
- Reduced fluid intake and urine output
🔗 More information on the common cold
3. Fevers
- Expected Duration: Up to 5 days (seek advice if lasting longer than 3 days)
When to Seek Medical Advice:
- Fever over 38°C in infants under 3 months
- Fever over 39°C in infants 3–6 months
- Fever not reducing with medication
Call 999 if your child has:
- A stiff neck
- Bothered by light
- A rash that doesn’t fade under a glass (see Glass Test below)
- Unusually cold hands and feet, pale lips, blotchy skin
- A seizure (febrile convulsion)
- Infants with an abnormal cry, agitation or floppiness.
How to Care for a Sick Child at Home
If your child has a fever, discomfort, or pain, paracetamol or ibuprofen (Calpol or Nurofen/Calprofen) can help unless they have an allergy or a medical condition that prevents their use.
These medications are useful for reducing fever and easing pain.
Key Home Care Tips
- Monitor hydration levels – Dehydration can occur quickly in unwell children. Signs include dry lips, fewer wet nappies, and lethargy. Keep offering fluids frequently.
- Monitor breathing – If your child is struggling to breathe, using extra muscles to breathe, or appears exhausted, seek urgent medical help.
- Know how long illnesses should last – If symptoms persist beyond the expected timeframe, consult a doctor.
- Ask your pharmacist for advice – Pharmacists can recommend over-the-counter treatments for children over 2 years old.
- Look out for serious symptoms – Some symptoms indicate a more serious illness and require immediate medical attention.
If you are concerned, always seek medical advice.
Why Is My Child Always Sick?
It is normal for children to experience eight or more colds per year, especially if they attend nursery or have siblings in school.
As long as they are well between illnesses, growing normally, and have good energy levels, there is usually no cause for concern.
However, if you are worried about frequent infections, consult a doctor.
In Summary
Understanding how long common illnesses last, when to seek help, and how to care for your child at home can help you manage their health more effectively.
Knowing the typical duration of common childhood illnesses provides reassurance, while recognising warning signs ensures prompt medical intervention when needed.
By maintaining good hygiene practices, ensuring proper nutrition, and staying up to date with vaccinations, parents can also help reduce the frequency and severity of illnesses in their children.
Encouraging adequate sleep, hydration, and a balanced diet further supports overall immunity.
If your child appears to have ongoing fatigue or is not recovering as expected, consulting a doctor should be considered.
Always trust your instincts—if something feels wrong, seek medical advice. No one knows your child better than you do, and seeking help early can lead to better outcomes.
Useful Resource
The NHS has produced some very useful information sheets for parents whose children have a cough or respiratory symptoms. Here are two examples below:
Video – Difficulty Breathing and Wheeze in Infants and Children
Below is a really useful video with Dr Ranj – showing what to look out for when you are worried about your child’s breathing:
My child seems to be getting sick a lot – should I worry about their immune system?
This is something that parents often ask. It is quite normal for a child to get 8 or more coughs and cold a year – especially if they attend nursery or have older siblings at school or nursery. As long as your child is well in between these episodes, growing normally and has plenty of energy, it is very unlikely that there is anything to worry about. If you are concerned, however, do book an appointment with a doctor to talk things through.
I have heard about the ‘glass test’ – how do I do this and what does it mean?
The glass test is a test to look for, what doctors call, a ‘petechial rash’. This is a rash that doesn’t go away when you press it, because it is caused by small collections of blood under the skin. Rashes are very common when children are unwell, but a rash that doesn’t go away when you press it, can be a sign of meningococcal septicaemia (blood infection in meningitis) or other serious illnesses. These are normally present in children who are very unwell. We advise that you use a glass to identify this rash so you can press on the rash and see it at the same time.
You can perform a glass test as below:
- Press the side of a clear glass firmly against the skin
- Spots/rash may fade at first
- Keep checking
- Fever with spots/rash that do not fade under pressure is a medical emergency
- Do not wait for a rash. If someone is ill and getting worse, seek medical attention immediately.
You can read more about the glass test at:
– www.meningitisnow.org/meningitis-exaplained/signs-and-symptoms/glass-test/
You can find more information about childhood illnesses and some really useful resources and tips at: www.what0-18.nhs.uk
Please note that information articles are not a substitute for direct medical advice. If you have any concerns, please seek personalised advice from a doctor.