Coughing can be more than just a minor inconvenience; it can be a symptom of something more serious. But have you ever wondered why we cough? What triggers this reflex that seems to come out of nowhere, and why does it sometimes stick around for days or even weeks?

In this Blog, we’ll explore what causes it, why we can’t always control it, We’ll also touch on the solutions-how to manage effectively and when it’s time to seek medical advice.

What is a Cough

Let’s start with the basics: a cough is essentially a protective reflex that helps clear your airways of irritants like mucus, foreign particles like dust or even harmful pathogens. When something stimulates the sensory nerves in your throat, lungs, or airways, it sends a signal to the brain, triggering a cough to expel whatever is causing irritation. It’s fast, efficient, and automatic, meaning it doesn’t require any conscious effort.

The process can be broken down into three primary stages:

1. Inhalation: A deep breath is drawn into the lungs.
   
   
2. Compression: The vocal cords close, and pressure builds up in the chest as the muscles involved in breathing contract.
   
   
3. Expulsion: The vocal cords suddenly open, and the pressure in the lungs forces air out at a high speed, carrying irritants out with it.
   

The rapid force can expel air from your lungs at speeds up to 500 miles per hour! That’s faster than the average speed of a fastball thrown by a major league pitcher

The Role of the Brain

Coughing isn’t just a mechanical process. It involves complex communication between the sensory nerves in your respiratory system and the medulla oblongata, the part of the brain that controls involuntary functions like breathing and heart rate.

Once the sensory nerves detect an irritant, they send signals to the brain via the vagus nerve to an area in the medulla known as the Nucleus Tractus Solitarius (NTS). This central nervous system area processes the sensory information.

Interestingly, the brain can also suppress or control coughing in certain situations, like when you’re trying not to huff during a meeting or in a quiet room. However, suppressing for too long can sometimes lead to more irritation, prolonging the cycle.

Causes

Some of the most common causes based on Duration and Symptoms:

Acute (Less than 3 Weeks)

Viral Upper Respiratory Infection (URI): If the symptom has been present for less than one week and is accompanied by other upper respiratory symptoms, it is likely due to a viral URI. Symptomatic treatment can be offered. During flu season, consider a nasal swab for influenza if the patient has a fever.

Acute Bronchitis: If it’s less than three weeks with no other notable symptoms, acute bronchitis is likely. Antibiotics are usually not indicated unless pertussis (whooping cough) is suspected.

COPD Exacerbation: If the patient is a smoker or known to have COPD, consider a possible COPD exacerbation. Treatment may include prednisone, inhaled bronchodilators (such as albuterol and ipratropium), and possibly antibiotics.

Subacute (3 to 8 Weeks)

If the cough was preceded by URI symptoms that haven’t since resolved, consider a trial treatment with prednisone to reduce inflammation.

Chronic (More than 8 Weeks)

With an unremarkable chest X-ray, consider the following common etiologies and their respective confirmatory tests or treatment trials:

Upper Airway Cough Syndrome (Post-nasal drip): This occurs when mucus from the nasal passages drips down into the throat, triggering a cough. It’s often a byproduct of allergies or sinus infections, Symptoms also include runny nose, sneezing, sinus pressure. Often treated with antihistamines or nasal steroids.

Asthma: Inflamed airway in which cough is typically dry and accompanied by shortness of breath or wheezing, diagnosed with spirometry and treated with inhaled corticosteroids or bronchodilators.

Acid Reflux: When stomach acid flows back up into the esophagus, it can irritate the throat, a condition known as gastroesophageal reflux disease (GERD).

In classic GERD, gastric contents reflux past the lower esophageal sphincter but remain within the esophagus, symptoms include heartburn, regurgitation, managed with proton pump inhibitors.

Smoking: This is often called a “smoker’s cough.” where irritants in cigarette smoke can inflame the airways.

Lung Cancer: A serious cause of chronic cough, often with other symptoms like weight loss and hemoptysis.

Genetic Conditions:

Ciliary Dyskinesia: A condition where the cilia in the airways do not function properly, leading to poor clearance of mucus and frequent respiratory infections.

Hereditary Immunodeficiencies: Various genetic conditions that affect the immune system and can lead to chronic cough due to recurrent infections.


ACE Inhibitors: A classic blood pressure medication known to cause cough in some patients. The reported incidence of this side effect varies widely from 1% to 33% of patients. Discontinue or switching to an alternative.

How To Approach

A thorough evaluation of patient is essential to determine the underlying cause. Here’s a structured approach to consider:

1. History Taking

Duration and Timing: Determine if the onset is acute, subacute, or chronic.

Productive vs. Non-productive: Assess whether the cough produces sputum or is dry.

Associated Symptoms: Inquire about the presence of:

Fever

Dyspnea (difficulty breathing)

Chest pain

Hemoptysis (coughing up blood)

Heartburn

Rhinorrhea (runny nose)

Nasal congestion

Weight loss

Medical History: Ask about:

Chronic lung disease

Immunosuppression

Smoking history

Use of ACE inhibitors or other medications

2. Physical Examination

Vital Signs: Check for fever, tachypnea (rapid breathing), tachycardia (rapid heartbeat), and hypoxia (low oxygen levels).

HEENT (Head, Ears, Eyes, Nose, Throat) Examination: Look for signs of upper respiratory tract infection or post-nasal drip.

Pulmonary Examination: Listen for wheezes, crackles, or decreased breath sounds.

Cardiac Auscultation: Assess for murmurs or other abnormal heart sounds.

Jugular Venous Pressure (JVP): Evaluate for signs of heart failure.

3. Diagnostic Tests

Consider:

Complete Blood Count (CBC) if infection is suspected

Chest X-ray: Consider an X-ray, especially if it’s chronic, persistent, or associated with red-flag symptoms.

Interpreting Abnormal X-rays

If a chest X-ray is ordered and found to be abnormal, further workup is indicated based on the findings:

Focal alveolar opacifications: Could indicate pneumonia or aspiration.

Reticular interstitial opacities: Consistent with interstitial lung disease (ILD).

Hyperinflation and flattened diaphragms: Suggestive of chronic obstructive pulmonary disease (COPD).

Lung nodules or masses: Possible lung cancer.

For most patients, a chest X-ray will often be unremarkable. This does not rule out serious pathology entirely but makes it less likely.

Red Flags for Serious Pathology

If a patient with a symptom exhibits any of the following red flags, a chest X-ray is warranted:

Concurrent dyspnea (difficulty breathing)

Hemoptysis (coughing up blood)

Chest pain

Weight loss

Jugular venous distension

Significant smoking history

Elderly or at risk for aspiration

Tachypnea (rapid breathing)

Hypoxemia (low blood oxygen levels)

Abnormal findings on cardiac or pulmonary examination

Signs of sepsis

How To Manage

Treatment varies depending on the underlying cause. Here’s a breakdown of how to approach different types:

1. Productive (Wet) Cough

A productive cough brings up mucus, which helps clear your airways. Suppressing it could cause more harm than good by trapping mucus in the lungs, potentially leading to an infection.

Effective treatments include:

• Expectorants: Medications like guaifenesin thin mucus, making it easier to expel.
  
  
• Hydration: Drinking plenty of fluids helps loosen mucus in the lungs.
  
  
• Humidifiers: Adding moisture to the air can soothe irritated airways and reduce coughing.
  

2. Dry Cough

A dry cough, often caused by viral infections, allergies, or irritants, doesn’t produce mucus. These coughs can be treated by calming the reflex itself by using:

• Cough Suppressants: Over-the-counter medications like dextromethorphan block the cough reflex to reduce the urge to cough.
  
  
• Honey: Research suggests that honey may be just as effective as some cough suppressants, particularly in children over one year old.
  
  
• Throat Lozenges: These can help soothe irritation in the throat, reducing the frequency of coughing.
  

When to see a Doctor

Sometimes, a cough is a sign of a more serious condition. If your cough persists for more than a few weeks, or if you experience symptoms like shortness of breath, chest pain, or coughing up blood, it’s important to seek medical advice

Conclusion

Coughing may be annoying, but it’s also an essential defense mechanism that helps protect your airways. A thorough evaluation, including history, physical examination, and appropriate diagnostic tests, is essential in determining the cause of a cough.

Depending on the duration and accompanying symptoms, treatment may vary from symptomatic management to specific interventions based on the suspected underlying cause.

By taking simple steps like using the right medications, staying hydrated, and knowing when to see a doctor, you can minimize the impact on your daily life—so you can finally breathe easier.