Cough is a common symptom of many different illnesses, ranging from mild to severe. Determining the strain or cause of a cough can help guide appropriate treatment options. This article will explore the most common strains and causes of coughs.
Common Cold
The common cold is one of the most frequent causes of cough. Colds are caused by viruses, like rhinovirus, coronavirus, adenovirus, or respiratory syncytial virus (RSV). There are over 200 known virus strains that can cause the common cold.
Cold symptoms often start with a sore throat, runny nose, congestion, sneezing, and cough. The cough from a common cold is usually dry and hacking initially. It may become looser after a few days. Colds are generally mild illnesses that resolve on their own within 7-10 days. Treatment focuses on symptom relief.
Influenza
Influenza (flu) is another viral infection that frequently causes cough. Influenza is caused by influenza A, B, C, or D viruses. New flu strains emerge each year, which is why flu vaccines are updated annually.
Influenza cough often starts dry but usually becomes productive with thick mucus. Other flu symptoms include fever, body aches, headaches, fatigue, and sore throat. Flu cough can last 1-2 weeks or longer. Prescription antiviral medication like Tamiflu can help shorten the duration if taken early on.
Pertussis
Pertussis, also called whooping cough, is a highly contagious bacterial infection caused by Bordetella pertussis bacteria. Pertussis is known for uncontrollable, violent coughing fits followed by a high-pitched “whoop” sound as air is inhaled.
Pertussis cough typically starts out mild like a common cold, then after 1-2 weeks, severe coughing fits begin. Coughing fits can recur for up to 10 weeks. Antibiotics like erythromycin are used to treat pertussis. The DTaP vaccine protects against pertussis.
Mycoplasma Pneumonia
Mycoplasma pneumonia is caused by Mycoplasma pneumoniae bacteria. It has symptoms similar to other respiratory infections but is sometimes called “walking pneumonia” because symptoms are often milder.
Cough from mycoplasma pneumonia is typically dry at first and can become productive. Other possible symptoms include low grade fever, headache, sore throat, and fatigue. Mycoplasma pneumonia is treated with antibiotics like azithromycin or levofloxacin.
Chlamydia Pneumonia
Chlamydia pneumonia is caused by Chlamydophila pneumoniae bacteria. It accounts for 10% of community-acquired pneumonia cases. Symptoms are usually mild.
The cough from chlamydia pneumonia is often dry, hacking, and can cause chest pain. Other symptoms may include fever, shortness of breath, and sore throat. Antibiotics like azithromycin, levofloxacin, or doxycycline are used for treatment.
Bordetella Parapertussis
Bordetella parapertussis causes a whooping cough-like respiratory illness. It is related to the bacteria that causes pertussis but is a distinct strain. Parapertussis cough can cause violent coughing fits but no “whooping” sound.
The cough typically arises 1-2 weeks after initial cold-like symptoms. Fevers are uncommon. Parapertussis is usually milder than pertussis. Antibiotics may be used for treatment and can help reduce severity and duration if started early.
Respiratory Syncytial Virus (RSV)
Respiratory syncytial virus (RSV) usually causes cold-like symptoms but can also lead to bronchitis or pneumonia, especially in infants. RSV accounts for over 75% of all bronchitis and pneumonia cases in infants under 1 year.
Cough from RSV often starts dry and becomes wet and congested. Symptoms like runny nose, sore throat, and fever generally appear first. RSV cough typically lasts 1-2 weeks but can persist longer in some cases. Supportive treatments help manage symptoms.
SARS-CoV-2 (COVID-19)
SARS-CoV-2, the virus that causes COVID-19, commonly causes cough. The most prevalent COVID strain currently in circulation is Omicron and its subvariants, like BA.5.
Cough from COVID can be dry or productive. Other symptoms may include fever, shortness of breath, fatigue, headaches, loss of taste/smell, and body aches. COVID cough tends to last 1-4 weeks on average. Antiviral medications like Paxlovid are sometimes used to treat high-risk patients.
Adenovirus
Adenoviruses cause about 10% of acute respiratory infections in children. They lead to cold-like symptoms but can also cause pneumonia, bronchitis, and pinkeye.
The adenovirus cough is often severe and hacking initially, then becomes looser. Other symptoms like sore throat, congestion, and fever typically appear first. Most adenovirus infections go away within 10 days. Severe cases may warrant antiviral medications.
Parainfluenza Virus
Human parainfluenza viruses (HPIVs) are a common cause of lower respiratory illness, particularly in infants and young children. There are four main HPIV types – 1, 2, 3, and 4.
Parainfluenza cough is typically dry and hoarse initially, then becomes wetter. Other symptoms can include runny nose, congestion, sore throat, and fever. Treatment focuses on relieving symptoms and managing complications like pneumonia.
Acute Bronchitis
Acute bronchitis is temporary inflammation of the airways to the lungs. It’s usually caused by a virus – like those that cause colds or flu. Less often, bacteria are the cause.
Acute bronchitis cough starts dry and painful, then brings up thickened mucus as the infection progresses. Other symptoms can include low fever, chest discomfort, and shortness of breath. Bronchitis cough usually lasts 1-3 weeks and goes away on its own.
Pneumonia
Pneumonia is lung inflammation usually caused by a bacterial, viral, or fungal infection. Common causes include viruses like flu or RSV and bacteria like Streptococcus pneumoniae.
Pneumonia cough is often productive with thick or blood-tinged mucus. Other symptoms include high fever, chest pain, shortness of breath, and rapid, shallow breathing. Pneumonia requires medical treatment with antibiotics, antivirals, or antifungals.
Asthma
Asthma is a chronic lung condition characterized by inflammation and narrowing of the airways. It’s triggered by allergens, irritants, respiratory infections, exercise, and other factors.
Asthma cough is often worse at night or early morning. Coughing episodes may come and go with asthma flare-ups. Wheezing and shortness of breath are common too. Asthma is managed with medications like bronchodilators and inhaled steroids.
Chronic Obstructive Pulmonary Disease (COPD)
Chronic obstructive pulmonary disease (COPD) refers to chronic bronchitis and emphysema – diseases that obstruct airflow from the lungs. It’s usually caused by long-term exposure to cigarette smoke or air pollution.
COPD cough is typically a chronic, mucus-producing cough. COPD also causes wheezing, shortness of breath, and chest tightness, especially with exertion. Treatment aims to manage symptoms with bronchodilators, steroids, oxygen therapy, etc.
Lung Cancer
Lung cancer, especially non-small cell lung cancer, can cause cough in its early stages. As lung tumors grow, they can irritate the airways and lead to persistent coughing.
Cancer cough may be dry or produce phlegm. Over time, it tends to progress and worsen. Other possible signs of lung cancer include recurring infections like pneumonia or bronchitis. Lung cancer screening is recommended for at-risk individuals.
Heart Failure
Heart failure means the heart isn’t pumping adequately to meet the body’s blood and oxygen needs. Fluid can back up into the lungs as a result.
Cough from heart failure often worsens at night or when lying down. Cough may produce white, foamy phlegm or pink, blood-tinged mucus. Shortness of breath, wheezing, and swelling are also common symptoms. Treatment involves medications and lifestyle changes.
Gastroesophageal Reflux Disease (GERD)
Gastroesophageal reflux disease (GERD) results when stomach acid backs up into the esophagus and throat. Chronic GERD can cause damage and scarring of esophageal tissue.
GERD cough is typically dry and chronic. It can be worse after eating or when lying down. Heartburn, regurgitation, and sore throat are other common reflux symptoms. Avoiding triggers, diet changes, and antacid medication can help manage GERD.
Postnasal Drip
Postnasal drip describes mucus drainage from the sinuses into the throat. It can be caused by allergies, chronic sinusitis, or environmental irritants.
Postnasal drip leads to chronic throat clearing and coughing. The cough is often worse at night. Other symptoms may include runny nose, congestion, and sore throat. Treatment involves managing the underlying cause and symptoms.
Environmental Irritants
Environmental irritants like chemicals, smoke, pollution, mold, and strong fumes can trigger coughing. Cough from irritants is typically dry and hacking.
Depending on the irritant and exposure over time, cough may resolve quickly once the irritant is removed, or it can become chronic and require further treatment. Identifying and minimizing exposure to triggers is key.
Angiotensin-Converting Enzyme (ACE) Inhibitors
Angiotensin-converting enzyme (ACE) inhibitors are medications used to treat high blood pressure, heart failure, and diabetes complications. A dry cough is a common side effect.
ACE inhibitor cough is a persistent, dry cough that arises within months of starting therapy. It goes away if the medication is stopped. If ACE inhibitors are needed for treatment, alternatives may be considered to alleviate the cough.
Cough Analysis
Key characteristics of a cough can provide clues to help determine the cause:
- Wet/productive vs dry cough
- Short and hacking vs deep chest cough
- Constant vs episodic/paroxysmal coughing fits
- Onset sudden vs gradual over time
- Associated symptoms like fever, wheezing, etc.
- Triggers like position changes, eating, irritants, etc.
Identifying patterns and details of the cough along with the person’s medical history can aid diagnosis. However, many causes lead to similar coughs. Diagnostic tests like chest X-rays, CT scans, lab tests, and lung function tests may be needed for confirmation.
Conclusion
Cough is a symptom of numerous diverse medical conditions from the common cold to lung cancer. Infections like cold and flu viruses, bacteria like pertussis and mycoplasma, and irritants like smoke cause acute coughs, while diseases like asthma, COPD, GERD lead to chronic coughs.
Careful evaluation of all cough characteristics and symptoms is needed to properly diagnose the cause. However, coughs from different illnesses frequently overlap. Additional medical investigation is often required to pinpoint the strain or source of a troublesome cough.
