Colds and flu
The runny nose, sore throat or "bunged up" feeling of a cold is caused by one of many viruses, called rhinoviruses that can infect the upper part of the breathing system (upper respiratory tract). Influenza - or flu - has similar symptoms but tends to be a more severe illness. In vulnerable people it can be dangerous.
Fighting flu
Although a cold can make you feel miserable, colds are usually "self limiting". This means the body fights off the infection and the cold is cured without the need for specific medical treatment.
The flu season
Most cases of flu occur between December and March and during Haj season.
How do you catch colds and flu?
The viruses responsible for colds are spread from person to person as droplets in the air. Sneezing or coughing produces more droplets and helps to spread the infection. Touching infected surfaces, such as door handles or when shaking hands, and then passing the virus from the hands to the mouth is another route of infection for viruses.
Infected people can spread the viruses from two days before the symptoms of the illness start and up to four days afterwards. Colds can occur all year round but are more common in the winter months. On average, adults catch two to three colds each year. School age children can have twelve or more colds in a year.
Symptoms
Colds
The virus multiplies in the soft, warm surfaces found in the nose, throat, sinuses, the windpipe (trachea) and the breathing tubes (the bronchi). Consequently, it is these areas where the symptoms usually occur. Typically, there is a blocked or runny nose, sneezing, sore throat and a cough. There may also be a fever, aching muscles and fatigue. The symptoms usually last for a week.
Flu
The symptoms are similar to colds but the muscle aching is usually more severe and the fatigue may last for a few weeks after the illness has cleared up. There is likely to be a fever and there may also be loss of appetite, nausea and sometimes vomiting and diarrhoea, especially in children.
Complications of flu
To most healthy adults, flu can be just like a nasty cold. However, young children, the elderly and people with certain chronic medical conditions are susceptible to potentially serious complications. These are mostly related to a bacterial infection of the lungs (pneumonia) or of the ears, nose and throat. In children under about six years, fits – known as febrile convulsions – can occur as a result of the high body temperature. People living in residential or nursing homes and people with the following conditions are at greater risk of complications:
- asthma
- chronic chest problems such as chronic obstructive pulmonary disease
- diabetes
- heart disease
- kidney diseases and kidney failure
- people with reduced immunity, such as people with HIV or people who have had their spleen removed.
Treatment
There is no cure for colds or flu. Antibiotics, which treat bacterial infections, do not work on viruses. However, home treatment can help to relieve the symptoms:
- Drink enough fluids to prevent dehydration.
- For adults, antipyretics can help to relieve fever and pain. Always follow the instructions carefully and take care to stay within the safe daily doses. It is easy to accidentally exceed these by using more than one product (eg tablets, capsules, a hot lemon drink) containing the same active ingredient
- Aspirin should not be given to children under 16 years old.
- Decongestants may clear congestion. Ask your pharmacist for advice on products that contain a decongestant.
- Steam inhalations with menthol or eucalyptus, or herbal products such as camomile, may help. Take care with the hot water.
- Eating a balanced diet with plenty of fruit and vegetables is sensible.
- Rest. Avoid strenuous exercise. Contrary to advertising claims for some cold and flu medicines, if you are unwell with a heavy cold and especially flu, carrying on as normal is not always advisable.
- Avoid tobacco smoke.
Complementary remedies
Supplements of vitamin C, zinc or the herbal remedies are popular for treating and preventing colds. However, there is no strong evidence that they are effective. At the doses recommended on products available in pharmacies and health food shops, the ingredients appear to be safe.
Antiviral medicines
For people in general good health, who are not elderly, no specific medical treatment – apart from the home care suggested above – is required for flu. For vulnerable groups, where it is important to prevent complications or spread of the virus, prescription only medicines may be needed.
There are several antiviral treatments, taken as tablets or as an inhaler (similar to the ones used for asthma). They have been shown to reduce the duration of flu but only by around one day, and then only if treatment is started within two days of the onset of the illness. GPs do not routinely prescribe antiviral medicines for flu.
Antibiotics may be given to treat any secondary bacterial infections such as a chest infection, ear infection or sinusitis.
Prevention
There are a few steps that can be taken to help prevent colds and flu:
- Isolation of people with colds and flu to prevent it spreading to other people, if practical.
- Regular hand washing and immediate disposal of used tissues.
- A healthy lifestyle – a balanced diet, rich in fruit and vegetables, and regular (preferably daily) physical activity.
- Not smoking – smokers are more likely to catch colds.
Immunisation
Having a flu jab each year significantly reduces the chance of catching flu. The immunisation provides protection against the flu virus for the whole flu season - the vaccination lasts for one year.
When to call the doctor
If the following symptoms develop with a cold, you should always consult a doctor, practice nurse or pharmacist for advice:
- severe vomiting or diarrhoea
- earache
- difficulty breathing
- skin rash
- uncontrollable cough
- cough with yellowy green or rust-coloured sputum (phlegm)
- extreme lethargy or drowsiness