Nocturnal Cough

What is Nocturnal Cough?

A cough is more than an annoying symptom – it’s actually a protective reflex your body uses to clear unwanted stuff like mucus, harmful substances, and infections from your throat and larger airways in your lungs. If this coughing response is weakened or missing, it can lead to serious, even possibly fatal, health issues. Interestingly, research shows that women are more likely to have chronic coughs, and their cough reflexes are generally more sensitive than men’s. A night-time cough can be especially troublesome, as it can interrupt sleep.

The cough reflex is made up of three parts:

* Sensory input: This detects what needs to be coughed up.
* Central processing: This is where your brain decides to initiate a cough.
* Response: This is the act of coughing itself.

Interestingly, your cough reflex can adapt over time. If you’re always coughing, it can lead to ongoing irritation and inflammation, causing changes in your lung tissue, and the body responding with an overly sensitive cough reflex.

Asthma, a common long-term lung disease, often comes with a night-time cough as one of its symptoms. For people with asthma, their symptoms often get worse at night and interrupt sleep, significantly impacting their quality of life. One particular study found that how much someone with asthma coughs at night could be a useful measure of how well their asthma is being managed. However, we need more information to fully understand the role of night-time coughing in asthma, such as what causes it and how it evolves over time.

What Causes Nocturnal Cough?

Nighttime coughing can be caused by issues related to breathing, non-breathing issues, and systemic problems, which affect the whole body.

The most common causes related to breathing include postnasal drip (mucus production), aftermath of an infection, and asthma. Outside factors such as active or secondhand smoking can also cause chronic coughing. Certain medicines like ACE inhibitors, beta-blockers, and non-steroidal anti-inflammatory drugs can result in a chronic cough too.

Some drugs causing scarring in the lungs (pulmonary fibrosis) include bleomycin, busulphan, methotrexate, carmustine, amiodarone, cyclophosphamide, and hydralazine. Other breathing-related causes include bronchiectasis (damage to the airways), bronchitis (inflammation in the tubes that lead to your lungs), COPD, cystic fibrosis, interstitial lung disease, lung tumors, sarcoidosis (groups of immune cells forming lumps), and tuberculosis.

There are several conditions related to the upper airway, like chronic enlargement of the tonsils, sleep apnea (interrupted breathing during sleep), GERD (stomach acid causing heartburn or chest pain), laryngeal issues (voice box issues), and foreign bodies in large airways that need to be ruled out. Non-breathing related causes include GERD, recurrent inhalation of food or liquids into the lungs, heart problems, pulmonary infarction (blockage in lung artery), and psychogenic cough (a cough without physical cause). There are some rare conditions such as abnormal heart rhythms, aortic aneurysms (bulge in the major blood vessel), couch only when lying down, complex tics sometimes found in Tourette syndrome, and vitamin B12 deficiency due to sensory neuropathy (damage to nerves that provide sensation).

Out of these conditions, cough associated with asthma, GERD, and upper airway cough syndrome account for 90% of instances of chronic cough.

COVID-19 can also cause long-standing symptoms, notably a persistent cough. ‘Post-COVID-19 syndrome’ is a term used to describe symptoms that occur during or after having COVID-19, and last over 12 weeks. More research is being conducted to understand the number of cases, the natural course of illness, and causes.

Risk Factors and Frequency for Nocturnal Cough

A worldwide survey covering 16 countries revealed that 30% of people reported having a cough at night, while 10% had a cough that produced mucus, and another 10% had a dry cough. However, conditions like chronic bronchitis, which can significantly impact people’s health, are often not properly represented. In the same way, specialist clinics might not give a true reflection of how common conditions like asthma are as causes of a long-term cough. This is because, particularly in Europe, doctors often try treating with asthma medication first.

• Around 30% of people have a cough at night, according to a global study from 16 countries.
• 10% of people have a cough that produces mucus, while another 10% have a dry cough.
• Chronic conditions like bronchitis are commonly underestimated even though they can lead to significant health issues.
• Specialist clinics might not accurately show how common conditions like asthma are as contributors to a chronic cough.
• This is particularly true in Europe, where doctors often start treatment with asthma medication.

Signs and Symptoms of Nocturnal Cough

A persistent nighttime cough should be evaluated depending on its intensity, severity, frequency, and sensitivity. Here are some points to consider during this evaluation:

• If the cough gets worse when lying down, it could indicate postnasal drip, acid reflux, chronic bronchitis, bronchiectasis, or heart failure.
• Clear phlegm can suggest a hypersensitive reaction.
• If the phlegm is filled with pus, it could be due to sinusitis or bronchiectasis. You should also check for tuberculosis in this case.
• Blood-streaked phlegm can be caused by cancers, tuberculosis, or bronchiectasis.
• A dry cough might be a side effect of ACE inhibitor medication.
• If a cough improves with the use of antihistamine medication, it’s likely a case of upper airway cough syndrome.

Nonetheless, certain symptoms may signal a serious condition. Pay attention to symptoms like a lot of phlegm production (potentially bronchiectasis), coughing up blood (which could be a sign of cancer or tuberculosis), systemic symptoms such as fever, weight loss, night sweats, and progressive tiredness (which can indicate conditions like tuberculosis, lymphoma, and lung tumors), and significant shortness of breath (which could be due to congestive heart failure, COPD, or fibrotic lung disease).

During a general health examination, the doctor will check for signs like clubbing (a sign of diseases like vasculitis, sarcoidosis, and cancers), swelling in the ankle and foot, and enlarged lymph nodes. They will also examine:

• The nose for a deviated septum, enlarged turbinates, polyps, and sinusitis.
• The ears for inflammation in the internal or external areas.
• The respiratory system to check for wheezing on both sides that could be due to COPD, bronchial asthma, or even heart failure. Wheezing could also be localized if there’s a blockage due to a foreign body or tumor.
• All other systems of the body.

Testing for Nocturnal Cough

If you’re dealing with a persistent, long-term cough, there are a number of tests and examinations your doctor might recommend. One of these is a chest x-ray, which is something that should be done in all cases. A normal chest x-ray coupled with a long-term cough could indicate a number of issues, including side effects from certain medications, Post-nasal drip, gastroesophageal reflux disease (GERD), and asthma. All these combined account for 90% of cases.

However, there are other potential causes for your chronic cough that might not show up on a chest x-ray. These include tumors, early interstitial lung disease (a type of lung disease that affects the space and tissue around the air sacs of the lungs), bronchiectasis (a condition that causes mucus to collect in the lungs), and certain types of infrequent pulmonary infections.

Taking a look at a sample of your sputum (mucus from your lungs) is another important step in figuring out what’s causing your cough. If the sputum is yellowish or greenish, a bacterial culture is needed. In some uncertain cases, doctors may also look for specific types of bacteria such as Mycobacteria. It’s also a good idea to examine the sputum for cancer cells and a condition called eosinophilic bronchitis.

Additional blood tests including erythrocyte sedimentation rate and C-reactive protein might be done to check for infections, cancer or connective tissue disorders. If your doctor suspects a specific type of pneumonia, he or she may check your cold agglutinin titers. In few instances, doctors may also require additional tests such as an ELISA test if they suspect HIV/AIDS.

There are a few more investigations that can be done if the cause of your cough is still unclear. A bronchial provocation test, which involves inhaling a substance that causes the Airways to spasm, can help diagnose asthma. If a foreign body is suspected in the airways or the chest x-ray shows some abnormal findings, a bronchoscopy may be performed. In this procedure, a thin tube (bronchoscope) is passed through your mouth or nose into your lungs, allowing the doctor to see what’s going on. For heart-related issues, an echocardiogram could be done.

Other tests include a 24-hour monitoring of the acidity in your esophagus or a test to measure the pressure inside your esophagus, particularly if GERD is suspected. You may also need to get your sinuses x-rayed. If no diagnosis can be made after all these investigations then the doctor might recommend a high-resolution CT scan.

To summarize, patients who have an isolated long-term cough that only comes at night, and who have normal physical examinations, chest x-ray, and lung function tests, are unlikely to have a serious lung condition.

Treatment Options for Nocturnal Cough

If you’re a smoker and you have a persistent cough, it’s advisable to quit smoking. Research has shown that a smoker’s cough often improves within eight weeks of quitting. If you’re taking a type of blood pressure medication known as an ACE inhibitor and develop a cough, your doctor may recommend stopping the medication to see if the cough improves within four weeks. If the cough continues even after stopping the ACE inhibitors, other causes of the cough will be considered. It’s also worth noting that these types of medications are also linked with the onset of asthma. Furthermore, try to steer clear of known air pollutants and irritants, like dust and chemical fumes, that can trigger coughing.

Treatment for what is known as upper airway cough syndrome depends on what doctors think is causing it: it could be an infection, allergy, or a condition called vasomotor rhinitis. Treatment options might include antihistamines (medications that help control allergy symptoms), antibiotics, rinsing your nasal passages with a saltwater solution (nasal saline irrigation), and sprays that reduce inflammation in your nose (known as nasal corticosteroids). Some of these sprays may also contain decongestants like pseudoephedrine to help unblock your nose. In addition, if asthma is confirmed, medications like beta-2 agonists and inhaled corticosteroids can provide relief within a week. Specialised tests can rule out a form of asthma that typically presents as a chronic cough (known as cough variant asthma). Medications like oral steroids or inhaled steroids can help if the cough is related to a condition called non-asthmatic eosinophilic bronchitis, where inflammation causes coughing. A cough that persists after an infection can be treated with a variety of medications, such as inhaled ipratropium and corticosteroids, and sometimes antibiotics that target infection-causing viruses or bacteria.

If heartburn or acid reflux (known as GERD) is causing your cough, treatment will likely include medications that help move food through your stomach more quickly (known as prokinetic agents), decrease stomach acid (H2 antagonists), or completely block the production of stomach acid (proton pump inhibitors). Eating a balanced diet, avoiding certain foods that trigger symptoms, and positioning yourself properly in bed can also help manage GERD-related cough. Your doctor may recommend trying proton pump inhibitors for 8 to 12 weeks to see if they help.

What else can Nocturnal Cough be?

A nighttime cough might be caused by problems in the throat, airways, stomach tract, or heart. Various conditions could be the root cause of this issue. In other words, doctors may consider the following possibilities:

• Respiratory tract infection caused by a virus (most common cause of an acute or subacute cough)
• Upper airway cough syndrome
• Asthma
• Gastroesophageal reflux disease (GERD)
• Non-asthmatic eosinophilic bronchitis (a type of lung inflammation)
• Bronchiectasis (damaged and widened airways)
• Bronchogenic carcinoma (a type of lung cancer)
• Chronic aspiration (inhaling food, stomach acid, or saliva into the lungs)
• Chronic obstructive pulmonary disease (COPD)
• Congestive heart failure
• Foreign body in the airway
• Interstitial lung disease (ILD)
• Tracheoesophageal fistula (an abnormal connection between the windpipe and esophagus)

In adults who have had a cough for more than eight weeks, it is usually due to a condition known as post-nasal drip, asthma, a type of lung inflammation known as eosinophilic bronchitis, or GERD. In children, the causes are the same, but bacterial bronchitis can also be a cause.

What to expect with Nocturnal Cough

The future outcome of a cough that occurs primarily at night usually depends on what’s causing it. If the cough is due to smoking, it typically starts getting better about eight weeks after one stops smoking. In cases where a certain type of blood pressure medication called ACE inhibitors (ACEI) therapy cause the cough, it generally improves within a month.

If the cough is caused by GERD (gastroesophageal reflux disease – a type of long-term acid reflux), it usually gets better only after the acid reflux problem is treated. However, cough associated with asthma, a condition that affects one’s airways and breathing, can last for several years.

Possible Complications When Diagnosed with Nocturnal Cough

Coughing at night can lead to disrupted sleep, which might potentially contribute to mental health issues in patients. A study conducted by Won and colleagues indicates that in adults, a constant cough can have a negative effect on their overall wellbeing. Those who have a chronic cough have a considerably lower score in the EQ-5D-3L index, a measure of health quality, compared to those without a chronic cough. This impact is noticeably more significant in women who are 65 years or older. Chronic coughing has also been linked with higher rates of anxiety/depression, pain/discomfort, and disruption of daily activities than it has with self-care or mobility.

• Disrupted sleep due to night time coughing
• Potential contribution to mental health issues
• Negative effect on overall wellbeing
• Greater impact on quality of life for women over 65
• Links to higher rates of anxiety/depression, pain/discomfort, and disruption of daily activities.

Preventing Nocturnal Cough

A cough at night can be a common and bothersome symptom. To manage it appropriately, it’s crucial to find and address the root cause. If you’re smoking cigarettes or using tobacco products, it’s recommended that you quit. Not only will this help improve your symptoms, but it could also prevent other health problems. It’s important to understand that smoking can cause or make your night-time cough worse. If a cough develops after taking ACEI, a type of medication, it would be beneficial to switch to a different one. A trial and error approach might be necessary to evaluate and effectively treat people with a persistent cough.