There could be a number of causes for your dry, irritating cough.
· We would initially consider the possibility that this is a residue of a viral infection – the same sort of infection that causes the common cold or flu. If this is the case, you should be able to place the start of your coughing to coincide with other symptoms such as a sore throat, blocked or runny nose.
· If colds or flu have been eliminated as a cause, we would then look at the possibility that this may be part of an allergy such as hayfever or allergic rhinitis, especially if your symptoms have coincided with the start of spring or summer. Don’t forget also that other airborne allergies such as to animal hair or house dust can also give you symptoms similar to hayfever.
· The third possibility is a minor digestive complaint which causes small amounts of stomach acid to escape, up your gullet and into the back of your throat. This is known as acid reflux and is a form of indigestion - you may also experience other symptoms such as bloating or flatulence. It is increasingly being recognised as a cause of coughing if viral infections or allergies have been eliminated.
· The last common cause of a dry cough is what we would simply term a nervous cough. This is more likely if you have been under some stress recently, coinciding with the onset of symptoms.
Of course, there are many other causes of a dry cough – but these are generally less common and require medical investigation. If your cough has lingered for more than 3 months, I would suggest that you speak to your doctor to rule these out.
I am sorry that the information you have provided me has not allowed me to give you a more definite answer, but hope that the information above is of help to you in working out the cause of your problem. Please let me know if I can be of any further help.