What Causes a Cough, and How Is It Treated?

What Is a Cough?

Coughing is a natural reflex that expels irritants, mucus or foreign objects from the respiratory tract. It protects the body in response to airway irritation or a stimulus such as a tumor.

How Does Coughing Occur?

When airway irritation is detected, the cough reflex begins. The respiratory muscles and diaphragm expand during a deep breath and then contract suddenly. This creates high pressure in the airways, helping expel irritants, mucus or foreign material.

Cough commonly accompanies colds, flu, allergies and respiratory infections. More serious conditions can also cause it, so persistent, severe coughing warrants medical assessment.

What Causes a Cough?

The most common causes include respiratory infections and conditions such as colds, flu, pneumonia, bronchitis, sinusitis, allergic reactions and asthma. Foreign material in the airways, chemical irritants, cigarette smoke and tumors may also cause coughing.

The main causes, from most to least common, include:

1. Viral Infections: Upper respiratory infections such as colds, flu and sinusitis are the most common causes of cough. They irritate the upper airways and trigger coughing.
2. Bacterial Infections: Bacterial infections such as bronchitis or pneumonia can cause coughing and mucus production.
3. Allergic Reactions: Coughing may follow exposure to allergens.
4. COVID-19: COVID-19, caused by SARS-CoV-2, which emerged in China in 2019 and spread worldwide, has become one of the most common diseases causing cough.
5. Asthma: Asthma narrows the airways and inflames the bronchial tubes, potentially causing cough, breathlessness and wheezing.
6. COPD: Chronic obstructive pulmonary disease (COPD) affects the lungs and may cause coughing. It can develop through smoking, air pollution, respiratory infections and exposure to other airway irritants.
7. Reflux and Gastroesophageal Reflux Disease (GERD): Stomach acid moving upward into the esophagus may cause coughing.
8. Smoking: Smoking damages and irritates the lungs, potentially causing cough. Smokers may also produce more mucus during coughing fits.
9. Medication Adverse Effects: Some medicines can cause coughing as an adverse effect, particularly certain blood pressure drugs such as ACE inhibitors.
10. Airway Irritation: Airborne pollutants, dust, cigarette smoke and chemicals can irritate the airways and cause cough.
11. Cystic Fibrosis, Bronchiectasis and Other Inherited Respiratory Conditions: Inherited respiratory conditions such as cystic fibrosis and bronchiectasis may cause cough, breathlessness and chronic bronchitis.
12. Swallowing Disorders and Aspiration: Swallowing disorders and aspiration of foreign material can irritate the airways and cause coughing.
13. Airway Foreign Bodies: Foreign material in the airways may cause cough, breathlessness and other symptoms.
14. Tumors: Lung cancer, mesothelioma (cancer of the lung lining), lymphoma, mediastinal tumors, cancers causing lung metastases and bronchial adenomas may cause coughing and other respiratory symptoms. Breast, colon, kidney, prostate and bladder cancers can spread to the lungs. 
15. Rare Causes: Cough may accompany less common conditions such as heart failure, pulmonary embolism or lung tumors. These possibilities require assessment, especially with other unexplained symptoms.
16. Postnasal Drip: Mucus produced in the nose and sinuses may drain down the back of the throat and cause coughing. It can occur with colds, allergies, sinusitis, chronic rhinosinusitis and other sinus problems.
17. Psychological Factors: Stress and anxiety may also cause coughing.

What Types of Cough Are There?

Recognizing cough types helps identify possible causes and associated conditions. Categories include:

• Acute Cough: This begins suddenly and usually lasts less than three weeks. Colds, flu and other upper respiratory infections may cause it.
• Subacute Cough: This lasts 3 to 8 weeks, generally as persistent coughing fits following an upper respiratory infection.
• Chronic Cough: This lasts longer than 8 weeks and may accompany asthma, allergic rhinitis, GERD, chronic bronchitis, COPD or more serious respiratory conditions such as a lung tumor.

Cough can also be classified by mucus production and the character of its sound:

• Dry (Nonproductive) Cough: No mucus is produced. It may accompany colds, flu and allergic reactions. GERD and medicines can also cause a dry cough, as can tumors compressing the airways.
• Wet (Productive) Cough: This involves mucus production and occurs with respiratory infections and diseases such as bronchitis, pneumonia, COPD and chronic bronchitis.
• Nighttime Cough: Coughing fits occur particularly during sleep. Asthma, GERD and heart failure may cause nighttime cough.
• Paroxysmal Cough: This involves severe, repeated coughing fits, typical of particular infections such as whooping cough.
• Spastic Cough: This involves coughing fits with sudden, forceful contractions and may result from airway irritation or infection.

How Is a Cough Relieved? Treatment Options

Cough is a symptom with many possible causes, including allergies, colds, flu, pneumonia, COPD, asthma and other respiratory infections. Treating a cough is closely linked to treating its underlying cause. Investigating that cause and addressing it is therefore important before turning directly to cough remedies.

Upper respiratory infections such as colds and flu are among the commonest causes. They are generally viral and may produce cough, runny nose, sore throat and headache. Viral infections usually resolve on their own, with treatment directed at symptoms. Options may include plenty of fluids, bed rest, fever-reducing medicines and cough syrups.

COVID-19 cough management may vary with underlying causes. In people with COVID-19, treatment also focuses on symptom relief alongside treatment of the disease itself . Symptomatic treatment may include cough syrups, bronchodilators (airway-opening medicines) and corticosteroids such as Prednol.

Asthma, a chronic condition involving airway inflammation, is another cause. Symptoms include breathlessness, chest tightness, cough and wheezing. Treatment uses medicines such as bronchodilator inhalers and steroids.

Cough may also be a symptom of an allergic reaction. An allergic cough develops after allergen exposure. Avoiding the triggering allergen or allergens is important. Allergic coughs are treated with antihistamines or medicines such as cough syrups.

People with chronic respiratory conditions such as asthma or COPD can control coughing by taking their medication regularly .

For some causes of cough, vaccines are available. Annual influenza vaccination, for example, may help prevent coughing caused by flu.

Rarely, a serious medical condition causes coughing and may require surgery . For example, a cough-causing tumor may be removed surgically or reduced in size using radiotherapy.

Symptomatic Treatment of Cough

Several options may relieve cough symptoms, including cough syrups, expectorants, antihistamines, decongestants and steroids.

• Cough syrups are particularly effective for dry cough.
• Expectorants help reduce coughing accompanied by mucus.
• Antihistamines and decongestants are particularly effective for allergic cough.
• Steroids are used especially in chronic respiratory conditions such as asthma.

Some measures taken at home may also help relieve cough:

• Humidification may reduce coughing by moistening the air and keeping the airways hydrated. Steam baths, humidifying devices or a simple wet towel may be used.
• Drinking plenty of fluids improves hydration and helps clear the airways, potentially easing coughing.
• Warm drinks may soothe coughing, particularly those containing honey, lemon and ginger.
• Honey can be used as a natural remedy to soothe the throat and reduce coughing.
• Throat lozenges may relieve symptoms by soothing the throat and reducing cough.
• Personal Measures: Rest and avoiding triggers such as cigarette smoke or dusty environments may also help.
• Respiratory Physiotherapy: This may relieve coughing by loosening mucus, clearing the airways and making breathing easier. Techniques include chest massage.

Caution When Treating Cough in Children

Do not give children, particularly those younger than 4, over-the-counter cough and cold medicines unless prescribed by a specialist. Excessive or incorrect use may cause serious, potentially life-threatening adverse effects and mask the underlying cause.

Because cough in children may signal an underlying condition, it should be managed under specialist supervision. Home measures only help relieve symptoms.

Important Information About Cancer-Related Cough

Cancer-related cough results from cancer cells spreading to the airways or affecting structures such as the lungs, larynx or lymph nodes. It is particularly common in lung cancer and lymphoma. It is generally persistent and dry, sometimes accompanied by mucus, and may occur with pain, breathlessness and fatigue.

Radiotherapy may relieve cancer-related cough. It uses high-energy X-rays or other radiation to kill cancer cells or slow their growth. Controlling cough can improve quality of life and ease breathing problems.

Prescription or over-the-counter medicines may also reduce coughing in patients with cancer.

Fenokodin is a cough suppressant and painkiller. Each tablet contains 20 mg codeine and 10 mg dionine. It is converted in the body to morphine, another opioid analgesic, helping relieve pain and cough. Turkey's green prescription is required to obtain it, and it must be used only on medical advice and with a prescription.

Precautions and adverse effects include:

• Dosage: Fenokodin dosage varies with age, weight and general health. Follow the prescribed dose and instructions. It is generally taken 2 or 3 times daily, 1 tablet per dose.
• Contraindications: Fenokodin is contraindicated in some situations. Consult your doctor particularly if you have respiratory depression, severe liver or kidney failure, headache or migraine.
• Adverse effects: Fenokodin may cause nausea, vomiting, dizziness, insomnia and constipation. More serious effects include allergic reactions, breathing difficulties and low blood pressure.
• Interactions: Central nervous system depressants, such as alcohol, sedatives, anxiolytics, hypnotics, antipsychotics and antidepressants, may increase respiratory depression, hypotension and sedation when combined with codeine.

Tips for Preventing Cough

Suggestions include:

• Hygiene: Wash your hands frequently and use antibacterial hand sanitizers to prevent the spread of germs.
• Immunity: Healthy eating and exercise are the two best ways to support immunity. A vegetable-rich diet, such as the Mediterranean diet, and regular exercise support defenses against many illnesses.
• Smoking and Air Pollution: Do not smoke, avoid cigarette smoke, and limit time in heavily polluted areas.
• Avoid Allergens: If you are prone to allergies, avoid triggers such as pollen, dust or animal hair. Keep your home clean and well ventilated.
• Protection in Cold Weather: Wear clothing protecting your head, neck and chest.
• Adequate Fluids: Drink plenty of water and warm beverages to keep the airways hydrated and help thin mucus.
• Humidifier: Consider using one to increase indoor humidity in dry conditions.
• Sleep: Get enough sleep to support immunity and the body's ability to fight infection.

Identifying the cause is important because cough may signal a serious condition. People with severe, persistent coughing should seek medical attention.

Summary

Cough is a symptom, and treatment depends on the underlying cause.

Management involves identifying and treating the cause. Home measures may relieve symptoms, but trying every remedy can lead to more serious problems. If coughing persists for an extended period, such as 7-10, consult a healthcare professional to investigate the cause and obtain appropriate treatment.

The best way to prevent coughing is to maintain a healthy lifestyle . Avoiding smoking, practicing good hygiene and exercising regularly may protect against coughing and respiratory infections.