Written by Dr Katie Stephens, GP
Dr Katie graduated from the University of Manchester in 2007 (MBChB) and completed her GP training in the West Midlands in 2012 (MRCGP).
What’s the difference between a cold and the flu?
Some people use the term ‘flu’ for symptoms that others would call ‘a cold’. Medically speaking, ‘flu’ is short for ‘influenza’ and we use this term when talking about cases suspected to be caused by an influenza virus. Symptoms of the flu can include fevers, chills, body aches, headaches and lethargy. It can lead to a more serious illness than a simple cold, especially in vulnerable groups of people, such as the elderly, pregnant women, and those with certain underlying medical conditions, including lung and heart problems.
A ‘cold’ is also caused by a virus, but it tends to be a less serious illness. The most common virus to cause a cold is aptly named the ‘rhinovirus’1 – not surprising, given ‘rhino’ means nose in Greek! Symptoms of a cold tend to be limited to the head or throat (think stuffy or runny nose, sore throat, sneezing, sinus congestion), and people are usually less unwell than with a flu2.
How can I avoid getting the flu?
One of the best things you can do is to get a flu jab (or flu nasal spray for children) if you are eligible. The NHS offers these for free to adults 50y and older, pregnant women, those with certain underlying health conditions and many children. (For more details on eligibility, see the Gov.uk advice here3.)
While the flu vaccine isn’t 100% effective, it does usually improve your chances of avoiding the flu. And, if you do end up getting the flu, you are more likely to have a shorter, milder illness if you’ve been vaccinated4. It is safe for most people, with the general caveat of avoiding it if you have a fever at the time, or having an alternative if you have an egg allergy. It can be normal to feel a little under the weather after a vaccination, but the vaccine itself doesn’t cause flu.
Another way to protect yourself is to ensure you wash your hands regularly, especially after getting in from being out, and before eating or handling food. Good hand washing should kill any germs on your hands and stop them from infecting you. Aim to scrub your hands with soap for 20 seconds (long enough to sing the ‘happy birthday’ song twice through). Try to get all parts of the back and front of your hands, including your nails and in-between your fingers. You might find this poster5 helpful to check how well you are doing at cleaning all the right places.
How can I treat the flu at home?
Many people who get both the flu or a simple cold can treat themselves at home. As these are both viral infections, antibiotics (which only treat bacteria, not viruses) don’t make a difference and aren’t needed. Symptoms typically last 7-10 days, although a cough can persist afterwards for 2-3 weeks6. The following measures tend to be helpful:
- Ensure you stay well hydrated. Fluids help your body fight infections and can prevent your kidneys becoming damaged by the infection. They can also help you feel better in yourself. Warm drinks with honey, lemon, or ginger, can ease throat pain and settle a dry cough. One way to check if you are drinking enough is to pay attention to the colour of your urine. If it is pale or see-through, this is a sign that you are well hydrated. If it is a strong or dark yellow, then head to the kitchen to make yourself a drink. (Some people with certain medical conditions, such as heart failure, must avoid drinking too much. If this is you, then stick to the personalised advice from your doctor about how much you are allowed to drink every day.)
- Over the counter medication. Simple painkillers such as paracetamol and ibuprofen won’t get rid of the infection faster, but they will help you feel better in the meantime and improve symptoms from a fever. Don’t take ibuprofen if you have asthma, indigestion, or have been told by a doctor to avoid it. Other over-the-counter medications, such simple decongestants, can be helpful. Make sure you only use these for a few days, as instructed by the medication box or pharmacist. Using these for too long can cause a ‘rebound congestion’ to happen when you stop. You don’t need a prescription for these medications and can always ring your local pharmacist for advice.
- Steaming is a great way to get instant relief from nasal and sinus congestion. Boil a kettle then pour the water into a bowl. For an extra decongesting boost, put a few drops of Olbas oil in the water. Hold your head over the steam (drape a tea towel over your head to trap even more steam, if you like) and slowly breathe in through your nose and out through your mouth for 5 minutes. Olbas oil can be used without worrying about ‘rebound congestion’. You can do this multiple times a day.
And of course, it’s always sensible to do a Covid-19 test, especially if you have any of the usual symptoms, if you’ve been exposed to someone with it, or if it is going around your area. For more advice on when to test, see the NHS advice here7.
Even if you test negative, it’s wise to stay home if you’re feeling particularly unwell. Try to avoid being around anyone who might be vulnerable if they were to catch your illness (frail elderly people, young babies/children, pregnant women, people with weakened immune systems or long-term medical conditions).
When should I see a doctor?
As mentioned in the above section, antibiotics don’t help your body fight off viral infections any faster. So, having a cold or the flu doesn’t necessarily mean you need to speak to your doctor. However, some groups of people are treated with antiviral medication if the flu is suspected and they are in an ‘at-risk’ group and meet other criteria as well.
The ‘at risk’ groups include adults over 65 years old, children less than 6 months old, pregnant women (including up to 2 weeks after giving birth), and those with certain medical conditions, including weakened immune systems. If this is you (or a person you look after), and you think you (or they) have the flu, contact your GP.
It would also be a good idea to speak to a GP if you aren’t feeling any better after 7 days, or sooner if you have symptoms suggesting a more serious infection, such as feeling a little lightheaded, or mildly short of breath. If you can’t get through to your GP, please contact or NHS 111.
For more severe symptoms, such as real difficulty breathing, sudden chest pain, coughing up blood, severe confusion or feeling very faint, please ring 999 or attend A&E.
For further advice on when to seek medical attention, click here2.
Do I have the flu or Covid-19?
All of the symptoms that someone might get with the flu can also be symptoms of Covid-19. So, while you may have an idea of what the underlying virus is, the only way to know for sure is to do a Covid-19 test.
If you test negative but feel very unwell, it may still be best to postpone visiting any friends or family this holiday season that fall in the at-risk group (e.g., elderly relatives, pregnant women) until you are better. (You are usually the most contagious in the first 5 days of having the flu.) This is because the flu can still be dangerous for some people.
For more information, please see the references below.
- Mäkelä, M. J., Puhakka, T., Ruuskanen, O., Leinonen, M., Saikku, P., Kimpimäki, M., Blomqvist, S., Hyypiä, T., & Arstila, P. (1998). Viruses and bacteria in the etiology of the common cold. Journal of clinical microbiology, 36(2), 539–542. https://doi.org/10.1128/JCM.36.2.539-542.1998