I've had a cold for four months, what could be causing it?

GETTING TO THE HEART OF MEDICAL MATTERS

- Dr Rosemary Leonard

Q I've had a cold for more than four months. It started with a runny nose, and then a couple of weeks later I started coughing. I do sometimes cough during the day, but it mainly occurs when I lie down at night, and first thing in the morning. I'm otherwise well, have no chest pain and when I'm not coughing, I can breathe normally. I know colds are caused by viruses, so antibiotics don't help, but is there anything else I could try?

A You are right that nearly all colds, which cause a runny blocked nose, together with a mild fever, sore throat and sometimes a dry cough, are caused by viral infections. This means that antibiotics are of no benefit, and the symptoms should clear up in a week to 10 days.

There are so many different viruses that can cause colds it is possible to have one cold after another, but it would be very unusual to have even several colds for four months. The fact your symptoms are worse when you lie down suggests you could well have a postnasal drip.

Glands in the nose and throat continually produce around one litre of mucus a day, which moistens and cleans the lining of the nose, moistens the air we breathe, traps bugs, and helps to prevent infections. Increased production can lead to the mucus collecting in the throat, triggering coughing, and can be due to allergies, a change in temperature (particularly cold weather) and also hormonal changes, as it can occur in pregnancy and on the combined pill.