What is cold and flu?
These viral illnesses are common, contagious and spread easily. Most people recover quickly, but complications such as chest infections and pneumonia – the swelling of lung tissue caused by a bacterial infection – can occur.
What’s the difference between cold and flu?
People often describe a bad cold as the flu, when in fact, during a typical year, only six per cent of tests taken for suspected ‘flu’ prove positive. Here’s how they compare:
||Mild to moderate
||Mild to severe
|General aches & pains
||Severe and can last 2-3 weeks
||Usually 39 degrees or higher for 3-4 days
Colds and flu are spread by different viruses. There are more than 200 common cold viruses and just three strains of flu two of which affect humans – influenza A, B. Influenza B usually causes milder symptoms and is the virus most likely to affect children. These viruses are spread through droplets (sneezing and coughing) and after contact with shared items, including work surfaces, door handles or keyboards.
We're also more likely to catch a cold or flu in winter, and outbreaks peak between January and March. Some believe this is because we spend more time indoors during the winter months and in closer proximity to others. But experts at the Common Cold Centre at Cardiff University say a better explanation is possibly that our noses are colder in winter, and that cooling of the nose lowers resistance to infection. They argue that if this theory is correct then covering our noses with a scarf in cold weather could help prevent colds.
Most of us recognise the initial tell-tale cold symptoms of headache and sore throat, followed by a runny nose. Following the initial symptoms, sneezing, irritated eyes, nasal congestion and a cough also develop. Symptoms are usually at their worst after around three days.
Flu symptoms are more severe and include a temperature of between 38°C to 40°C, muscle aches and pains, exhaustion, sweating, a cough and nausea. Symptoms normally last between two and seven days unless complications develop. Some young children with flu may have febrile convulsions (a fit that occurs with fever).
How long do cold symptoms last?
Cold symptoms can last from 5 - 7 days, although herbal medicines, such as Pelargonium and Echinacea, can help reduce the duration and severity of symptoms. But you don’t usually need to contact your doctor if you have a cold or sore throat unless:
- The person affected is very young or very old and seems unwell
- Symptoms last longer than a week
- The infection spreads to your chest or inner ears
- You suffer from long-term lung conditions, such as asthma or chronic bronchitis
If you have a chronic lung problem your GP may recommend antibiotics. These won't make your cold go away any quicker, but will stop secondary infections, which can make your condition worse.
How long do flu symptoms last?
Flu symptoms are more severe than cold symptoms and usually last longer. If not treated with antiviral medicines or herbal remedies, flu symptoms can last from 7-10 days, and it can take 2-3 weeks (or more) until you feel completely well. There is also a risk of complication with influenza, including pneumonia, inflammation of the heart, fits and even sepsis.
Prevention is the best protection. For the most at-risk - people aged 65 and over on March 31st, 2018 (so you could currently be 64), pregnant women, children and adults with an underlying health condition or weakened immune system – you are eligible for an annual influenza vaccination. Consult your GP for more information.
Most of us don’t need to see a doctor to know we have a cold or flu, only if the symptoms are persistent, you suffer from any of the aforementioned health conditions, or you fit into the ‘at-risk’ category.
Who gets colds and flu?
Children get more colds than adults: every year most kids get around five colds compared to adults who get two or three and we tend to get fewer cold as we get older. Anyone can come down with a cold or flu but those at risk of complications include pregnant women, anyone over 65 and those with a long-term health condition, such as heart, lung, kidney disease or diabetes, as well as babies and young children. The elderly are especially at risk - particularly those in residential homes where the virus spreads rapidly.
If you have diabetes, keep a close eye on your blood glucose levels during any illness, including a cold as your glucose levels may rise so that you need your medication adjusted. If in doubt, always consult your doctor.
Babies and upper respiratory infections
Babies breathe mainly through their nose during the first few months of their lives, so an upper-respiratory infection which causes a blocked or stuffy nose is distressing for them. As well as interfering with breathing, a cold also affects feeding and sleeping. Sprays made from sterilised sea water are available to help cleanse passageways and help relieve a stuffy nose. If you are worried about a baby’s breathing always seek medical advice.
Flu can be more severe in pregnant women, and can lead to complications such as pneumonia as your immunity is naturally reduced. A flu vaccination is offered free on the NHS to women who are pregnant, to protect both mum and baby. This reduces the risk of complications (such as pneumonia), miscarriage, and premature delivery of a baby with a low birth weight. It’s safe to have a flu vaccine at any stage of pregnancy. Having a flu vaccination also passes antibody protection to your baby for the first few months of their life (1).
COLD: There is no ‘cure’ for the common cold. Antibiotics don't work against viruses and are only prescribed if you develop a bacterial chest, lung or ear infection. You can ease your cold symptoms by resting, drinking plenty of fluids, taking painkillers for aches and pains if needed, using decongestant sprays to help unblock your nose, or herbal remedies such as Echinacea or pelargonium.
FLU: Treatment for flu can include the above remedies for colds and most cases get better without medical treatment. Occasionally, however, antiviral drugs are prescribed, though these are usually reserved for people who are very ill. A flu jab will not help if you already have flu but can lower your risk of catching it in the future. This is given either as an annual injection or a nasal spray at the start of autumn, ideally.
Anyone in a high-risk group is advised to have the flu vaccine, which is available free on the NHS. It's also now available for some children. Receiving the annual flu jab won’t stop all flu viruses, but it will help speed recovery and reduce the severity of symptoms and risk of complications.