Ask Mayo Clinic: A cough that won't quit after 4 months could signal something serious

Dear Mayo Clinic: For nearly four months, I’ve had a cough that started with the flu and just doesn’t seem to be going away. Should I be concerned?Answer: A cough that lasts longer than eight weeks is considered a chronic cough and should be evaluated for possible serious conditions such as pulmonary infections, lung cancer or heart failure. Some red flags include coughing up blood, hoarseness, difficulty swallowing, new swelling in your feet, pneumonia that keeps coming back and smoking tobacco.However, these concerns may have already been addressed, and the cough persists. Coughs can be triggered by many types of receptors in the lungs, airways and larynx, and they tend to fall into three categories:Acute coughs last up to three weeks. The cough may be brought on by an infection, such as the flu.Subacute coughs last in the three-to-eight-week range.Chronic coughs are those that persist for more than eight weeks.During the acute and subacute categories, a primary care clinician may find ongoing symptoms of an infection, such as pneumonia or bronchitis, and prescribe antibiotics or recommend over-the-counter decongestants. They may also order a chest radiograph to confirm their diagnosis.Once a cough falls into the chronic category, then your healthcare professional will start looking for causes beyond the original infection. These causes might be underlying pneumonia, pulmonary fibrosis, bronchiectasis or an undetected cancer. But often, persistent coughs arise from conditions such as:asthma, including a variant called eosinophilic bronchitis;upper airway cough syndrome, which is when postnasal drainage tickles the back of the throat and triggers a cough;gastroesophageal reflux disease (GERD), in which acidic or nonacidic stomach content flows back up into the esophagus, causing heartburn, bloating, burping, voice changes, dental issues and coughing.Chronic coughs range from mild to intense and barking coughs, all of which can be debilitating and, for some patients, last for years. They may produce phlegm, occur only during the day or at night. People may experience chest and throat sensations, such as a tickle or scratch. Other triggers include talking, laughing, singing, changes in body position, fumes, dust, scents and odors.Patients may consult with a variety of specialists beyond their primary clinician to find the cause of their coughs, including a pulmonologist, allergist, or ear, nose and throat clinician; or they may reach out to a specialty chronic-cough center.There may be more than one cause behind a chronic cough, and each needs to be considered carefully.The first steps in any evaluation of a persistent cough are to talk through the history of the cough with the patient and:Determine if the person is smoking anything, including cigarettes, vaping and drugs such as marijuana.Review their medication list. Some ACE inhibitor blood pressure medications, such as lisinopril and ramipril, can bring on chronic coughing.Request chest imaging and pulmonary function testing.At a chronic-cough center, patients may undergo several tests that evaluate airway reactivity and inflammation, as well as asthma. Additional tests include inspecting the nasal passages, larynx and vocal cords. Any drainage also is examined for abnormalities and evaluated for upper airway cough syndrome.The clinician also will ask questions about GERD, including consumption of caffeine, alcohol, carbonated beverages, fatty or acidic foods, late-night snacking, and exercise routine. If GERD is suspected, additional tests can delve deeper into the relationship between reflux and a chronic cough.Other areas for evaluation include screening and testing for sleep apnea and checking for chronic airway abnormalities.Even with the best diagnostic evaluation and trials of therapies, the cough may persist. Then the focus turns toward finding a treatment that allows patients to cope with their chronic cough.Treatments may include:speech therapymedications, such as gabapentin, pregabalin, amitriptyline and duloxetineblocks of the superior laryngeal nerve, located in the upper part of the larynx or voice boxvocal cord therapiesIt really can take a village of healthcare professionals to determine the causes and possible cures or treatments of chronic coughs. For the patient, this path can be long and sometimes frustrating. That’s why it’s important to find a team of specialists who are as committed to finding an answer to a lingering cough as the patient is.— Sumera Ahmad, M.B.B.S., Pulmonary Medicine, Mayo Clinic, Rochester, Minnesota(Mayo Clinic Q & A is an educational resource and doesn’t replace regular medical care.This Mayo Clinic Q&A represents inquiries this healthcare expert has received from patients.For more information, visitwww.mayoclinic.org.)