A cough is the body’s natural response when something irritates the throat, airway, or lungs. Coughing every once in a while is normal, but when it persists or worsens, it can be a sign of a health issue. A dry cough can be symptomatic of a variety of conditions.
Dry Cough vs. Wet Cough
There are many types of cough, and the type of cough a person has helps the doctor determine what is causing it. One of the first things the doctor wants to know is whether the cough is wet or dry. Wet coughs bring up phlegm or mucous; dry coughs do not. The color of the mucous produced by a wet cough gives further hints as to the cause.
Chronic or Acute
Coughs, both wet and dry, are either acute or chronic. Acute coughs last for less than three weeks, while a chronic cough lasts for eight weeks or more — four weeks for children. It is possible for a cough to start dry and become wet over time.
Allergies and Asthma
Allergies and asthma are common causes of a dry cough. In this case, the cough is often seasonal and depends on what allergens are in the air. It is likely to develop alongside other allergy symptoms, such as sneezing and itchy eyes, nose, and ears. Dry cough from allergies happens because the airways swell in response to the allergen. In the case of someone who also has asthma, an allergen may cause wheezing and tightness in the chest.
GERD
Another condition that can cause dry cough is gastroesophageal reflux disease or GERD. One study shows that about 14 percent of people with GERD experience a cough as often as four to six times a day at least four days a week. Dry cough from GERD results from acid reflux irritating the back of the throat.
Post-Nasal Drip
Post-nasal drip, a slow trickle of mucous from the back of the sinuses into the throat, causes irritation and often results in a dry cough. A lot of things lead to post-nasal drip, including allergies, viral infections, irritants in the air, and pregnancy.
Medication-Related
A medication-related dry cough is a common side effect of ACE inhibitors, which doctors often prescribe to treat high blood pressure. A cough affects about 20% of people who take these medications. In one study, about 19 percent of people taking this class of medication discontinued it because of the side effects, mostly the dry, persistent cough.
Lung Infections
Viral and bacterial infections can cause either a wet or dry cough, depending on the infectious agent and how long the person has been sick. One example of this is whooping cough. Sometimes, people with whooping cough present with the characteristic whooping sound and thick mucous, but, for some adults and adolescents, a dry, hacking cough is the only sign.
Lung Cancer
Lung cancer does not usually present with any symptoms until it is quite advanced. Most diagnoses occur when a patient presents with weight loss, pain, and a persistent cough that is either wet or dry. A new cough that does not go away or that produces any amount of blood is concerning and should be evaluated by a doctor.
Heart Failure
A dry cough may be a sign that something is wrong with the heart. A pronounced cough, most often when lying flat, is a common sign of cardiac issues. Some people with heart failure or heart disease experience a dry cough while others produce thin, frothy mucous. Other signs include fatigue, leg swelling, and shortness of breath on exertion.
Treatment
Treatment of a dry cough depends on the cause. People with a chronic dry cough should stop smoking, and those taking ACE inhibitors may need to switch to another medication. Antihistamines can treat allergic causes, while bronchodilators address asthma and acid blockers can treat GERD. In the event of a bacterial infection, a person may need antibiotics. Over-the-counter cough medicines can help treat the cough itself, but they will not address the underlying cause.