When coughing sets in, a cold is usually not far behind. A runny nose, hoarseness, sore throat, headache, aching muscles: the typical cold has a number of unpleasant and uncomfortable symptoms, all of which add to the distress of the cough.

When the upper respiratory passages are infected and their mucous membranes are inflamed, doctors speak of a common cold. This is caused by viruses that our body can normally fight off quite effectively. But if our immune system is weakened - due to stress, pre-existing illness or poor diet, for example - viruses have less difficulty in starting a cold.

So here is some good advice: strengthen your immune defences if you feel weak, exhausted or had a chill. Take special caution if you are in contact with anyone suffering from a cold.