Is Your Cold Causing a Wet or Dry Cough?

A cough is a common cold symptom. When doctors evaluate a cough, they usually describe it as being either nonproductive or productive. A productive cough is a wet cough—it causes the body to expel mucus. A nonproductive cough, on the other hand, is a dry cough and does not bring up phlegm.

A cough from a cold is typically treated with over-the-counter cough syrup, but there are many varieties to choose from with different active ingredients. Here's how to determine the best medicine for your type of cough.

A nonproductive cough is one that does not bring up any mucus or other secretion. Also known as a dry cough, a nonproductive cough often is caused by some sort of irritation in the throat. Many people describe the irritation as a "tickling" or "scratchy" sensation.

While a cold is a common cause of a dry cough, a nonproductive cough may also be due to swelling of the airways, a condition often characteristic of asthma and bronchitis. The flu or other upper respiratory infection may also trigger a dry cough. Less commonly, heart failure, a collapsed lung, or lung cancer can manifest with a persistent dry cough.

If your cough persists or is severe, your doctor may perform tests to rule out other conditions, including:

• Asthma can be reliably diagnosed with spirometry. Spirometry involves a tool into which you breathe to measure the force of your breath and the capacity of your lungs.
• Gastroesophageal reflux disease (GERD), a disorder in which 40% of people will experience a dry cough, can be diagnosed with endoscopy (involving the insertion of a flexible scope into the esophagus and stomach) and an ambulatory pH acid test.
• Sleep apnea, for which cough is a feature in up to 44% of cases, can be diagnosed with an in-lab sleep test or a home version that can measure blood gases, heart rate, and airflow and breathing patterns.
• Vocal cord dysfunction, the abnormal narrowing of the larynx due to an inhaled irritant or extreme exercise, may require an allergist to evaluate allergic causes or a combination of stress tests and imaging studies to detect breathing abnormalities during exercise.

A cough that brings up mucus or other fluid, including blood, is a productive cough. It is often referred to as a chesty or wet cough because you can literally hear a gurgling obstruction during a cough.

Most coughs caused by cold or flu will go away after a few days. But if a cough is productive, lasts more than a few weeks, and involves fever, greenish-yellow phlegm, and shortness of breath, it may be due to a lung infection of some sort.

Pneumonia, acute bronchitis, bronchiectasis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis are among the other possible causes of a productive cough. GERD can also sometimes cause a chesty cough if there is severe inflammatory damage to the esophagus.

Your doctor may perform tests to diagnose the cause of a productive cough including:

• Chest X-ray
• Sputum analysis (in which coughed-up mucus or phlegm is evaluated in the lab for infection)
• Blood tests (to check for signs of infection)
• Pulmonary function tests (including spirometry and blood gases)

The treatment of a non-productive or productive cough depends on the underlying cause.

If the cause of a non-productive cough is limited to a cold, a cough suppressant containing dextromethorphan may be enough to provide control.

Other treatments may include inhaled bronchodilators for asthma, antacids and proton-pump inhibitors for GERD, antihistamines for allergies, and continuous positive airway pressure (CPAP) breathing machines for sleep apnea.

For a productive cough due to a cold, an expectorant can loosen and thin the mucus so that it's easier to expel. Your doctor or pharmacist can point you in the direction of an over-the-counter expectorant that's safe and right for you. Humidifiers and breathing in steam can also help.

Chronic productive coughs are more concerning and may require aggressive treatment of the underlying causes. Infections may require antibiotic therapy, while chronic disorders like COPD and cystic fibrosis may require ongoing care with oxygen therapy, inhaled or oral medications, and pulmonary rehabilitation.

A cough accompanying a cold typically lasts a week or two and can be treated with over-the-counter medicine. Call your doctor if:

• Your cough is severe.
• Your cough lasts more than three weeks.
• You cough up yellowish-green, pink, or bloody sputum.
• You have a fever of over 103 degrees F.
• You experience shortness of breath or rapid heartbeats.