What is a cold?

The common cold bedevils our winters and accounts for about 27m days off work a year in the UK. The culprit is usually a viral infection that causes inflammation of your nose, throat, sinuses and larynx. It is often called an upper respiratory tract infection (URTI) to distinguish it from more serious infections of the lower respiratory tract. Colds aren’t dangerous to most people, but they can be very unpleasant even though they last only a few days. Unfortunately, you can’t do much about them.

Who gets colds?

We all do, but they are more prevalent in winter because we herd together indoors with other infected people, who pass on the virus. Children get up to five colds a year and adults get two or three. Kids are walking reservoirs of viruses, and adults who are in contact with kids, such as teachers, are more prone to URTIs. Pre-school children in daycare get more colds, but no one is suggesting it does them any harm in the long run. People who smoke, have diabetes, impaired immunity or asthma are more likely to develop complications such as pneumonia from a cold.

How can I avoid getting one?

Live like a hermit in a well-sealed cave. If that’s not an option, there’s nothing you can do. It’s up to the people with colds to take action. They should cover their mouth and nose when sneezing or coughing, wash their hands, throw snotty tissues into a closed bin, and stay off work or school until they have got their streaming nose under control. Wearing a mask when you have a cold is very socially aware, but looks a bit odd and is probably overkill unless you have a particularly virulent bug – in which case, you should stay home.

Professor Meenu Singh, a specialist in children’s lung conditions, who works in Chandigarh, India says: “I don’t wear a mask even in swine-flu season in India. I do take supplements containing vitamins and minerals, but not specifically to avoid colds. If I get throat pain, I rely on saline gargles and may occasionally take steam inhalation – no antibiotics and no herbal remedies.”

Will supplements protect me?

Maybe. Zinc supplements may help to prevent colds. Garlic, homeopathy, vitamins C and D and echinacea won’t harm you, but there is no good evidence that they protect you either. There is some positive, but poor-quality evidence that probiotics, the “good” bacteria in the gut, can reduce the incidence, duration, severity and impact of colds. There is no reason not to eat yoghurt to boost your intake of probiotics while the scientists try to sort out whether they do work, and if so, how much we need and which types.

What should I do if I get a cold?

Most people will get over a cold within a few days. The general advice is to rest, drink adequate fluids and try not to spread it to others. Professor Bruce Arroll of the University of Auckland in New Zealand says there is no evidence that wrapping up warm, or eating chicken soup help – and steam inhalation probably doesn’t work either. “There’s limited evidence for paracetamol, but anti-inflammatories do have some general benefits for aches and pains. Oral and nasal decongestants probably work, although the evidence is low-quality. Ipratropium nasal inhalers [available on prescription only in the UK] work for a runny nose, and Vicks in children is probably OK,” says Arroll.

Is a cold vaccine on the way?

No. Vaccines boost the immune system against particular viruses. But you need to know which viruses to target. And common colds can be caused by a wide range; most are from a family called rhinoviruses, but others such as coronavirus and influenza may be responsible. Often, no particular virus is found, so developing a vaccine is almost impossible.

Will there be a cure for colds in my lifetime?

Probably not. There has been some enthusiasm for the antiviral drug, interferon, delivered as a nasal spray. In one trial, it reduced symptoms such as cough, runny nose and feeling ill, but the participants took other drugs (antihistamines and ibuprofen) at the same time. Interferon is expensive and can itself cause flu-like symptoms, so it may be a sledgehammer to crack a nut. A more likely candidate is a spray that coats the lining of the nose with a gel to stop viral particles getting past your nostrils.

Why can’t I have antibiotics?

Colds are usually caused by viruses, and antibiotics don’t kill viruses. Occasionally, bacteria that live in the respiratory tract are found in people with colds, but eradicating them with antibiotics won’t speed up your recovery and isn’t necessary. Rarely, colds develop into ear infections, severe sinusitis or pneumonia, and then antibiotics are needed. Symptoms suggesting a serious complication would be high fever, cough with green sputum, earache or facial pain.

I’m better. Why am I still coughing?

After a viral illness, there may be inflammation around the airways that causes cough and wheezes. Cough medicines shouldn’t be given to young children, and adults should be aware that there’s no evidence either way on their use. Inhaled corticosteroids (typically used in a brown puffer or inhaler) help people with known asthma and it is possible that non-asthmatics may benefit, too. If you are breathless, have a cough for more than four weeks, are getting worse or have worrying symptoms like weight loss or blood in the sputum, you should see your GP for further investigation.