Physiology of the cough
Why do we all cough? We have all coughed in our lifetime, and there is no-one who escapes coughing from time to time. A cough has the function of clearing our airways of any obstruction. This can be fluid, phlegm, or a foreign body. It is a response to build up enough pressure in our chest to expel any obstructions so our airways are clear to breath again. When we detect any obstruction, or if we feel that our airways are not working as they should be then we tend to cough.
Difference between a wet cough and a dry cough
A wet cough normally occurs when we have an infection. Anything such as pneumonia or a chest infection usually results in a phlegmy cough. The body produces a lot of inflammatory fluid to fight the infection, and a wet cough is produced. However, a dry cough does not have any fluid, and is just as a result of irritation. It can be just as disabling as a wet cough, and potentially can last a lot longer.
Diagnosis
If you are worried about a cough that has not gone away you should consult medical advice. A doctor or nurse may ask you more questions about your medical history and examine you. They may weigh you, and send you for blood tests and an X-ray if they think it is necessary. Normally most physicians are able to diagnose you quickly and easily.
Possible causes
There are many dry cough causes, from infection to allergy, and from trivial causes to serious ones. The causes can be divided up into different main categories:
Allergy
One of the biggest dry cough causes is an allergy. This may be allergy to grass, dust, or animals. These are the most common forms of allergy, although it is possible that you can be allergic to anything. Allergens in the air are a prime source of dry cough causes as these allergens cause irritation of the airways. This can cause muscles surrounding your airways to become inflamed. The only way to clear the obstruction is to cough, hence you get a dry cough. Your doctor can diagnose this by taking a history and running some breathing tests. He or she may also run an allergy test so that you know exactly what to avoid. In the meantime, taking antihistamines may help with your cough.
Asthma
It is estimated that in the Western world up to one in six of us suffers from some form of asthma at some point in our lives and is one of the more common dry cough causes. Typically asthma affects us more at night, and after hard exercise. Our airways can become more sensitive, and we can end up coughing when there is nothing to cough up. Your doctor can normally tell whether you suffer from asthma by running breathing tests and seeing if you do better when you use an inhaler.
Autoimmune disorders
There are some rare conditions that can affect the lungs. Rare conditions such as sarcoidosis can result in the body attacking itself and damaging the lungs. This can result in a dry cough, weight loss and make the sufferer very concerned about the possible dry cough causes.
Cancer
The biggest fear for many people is cancer. This is an uncommon one of the dry cough causes, but it is worth mentioning. If you have had a cough that has not gone away for a long time, and you have been losing weight then you should see your doctor. If you smoke, or live an unhealthy lifestyle, this can all make cancer more likely. Usually this can be seen on an X Ray or a CT scan of your chest. Your doctor will be able to see if this is appropriate for you.
Infection
There are some infections that do not cause you produce a lot of phlegm. Some viral infections can linger for a few days and still one of the dry cough causes. Equally if you are recovering from a major infection then coughing can just be your lungs getting used to be able to inflate normally again and is nothing to worry about.
Medication
There are plenty of medications that cause people to cough, and pills are a very common one of the dry cough causes. One of the most common are blood pressure tablets that act on the lungs. These tablets have an undesirable effect of causing coughing in up to 10% of people who take them. If your cough has started once you have taken your new medication, then it is worth seeing if there is an alternative.
Lung fibrosis
Some older people may suffer from a condition called lung fibrosis. This occurs as the lungs begin to scar over. No-one knows why this happens, but it can cause a dry cough in the elderly alongside weight loss. This can normally be discovered on examination and confirmed with an X ray.
Treating a dry cough
The most important thing to do about a dry cough is to make sure you know what is causing it. Many of the dry cough causes are entirely reversible, and should not be a cause for concern. There is usually a tablet or even just reassurance that you can take to make yourself feel better. If it is something serious, then it is best to get yourself diagnosed so that you can have your peace of mind rather than worry yourself with possible dry cough causes.