Coughs fall into a few distinct categories based on how they sound, how long they last, and what triggers them. By paying attention to these three things, you can usually narrow down what’s going on and whether it needs attention.
Dry Cough vs. Chesty Cough
The first and simplest distinction is whether your cough produces mucus. A dry cough feels tickly or scratchy and brings up nothing. A chesty (or “productive”) cough produces phlegm as your airways try to clear themselves. This single detail points in very different directions.
Dry coughs are common with viral infections in the early stages, allergies, acid reflux, asthma, and certain blood pressure medications. Chesty coughs typically show up with chest colds, bronchitis, pneumonia, and sinus infections where mucus drains down the back of the throat. If you’re coughing up phlegm, its color matters: clear or white is usually less concerning, while thick green or yellow phlegm suggests a bacterial infection that may need treatment.
How Long You’ve Been Coughing
Duration is one of the most telling clues. Doctors break coughs into three categories:
- Acute cough: less than 3 weeks
- Subacute cough: 3 to 8 weeks
- Chronic cough: more than 8 weeks
Acute coughs are overwhelmingly caused by upper respiratory infections, including the common cold, flu, COVID-19, and RSV. These viral infections typically run their course in one to two weeks, and the cough usually follows. If your cough started with cold or flu symptoms and you’re still in that window, you’re likely dealing with a straightforward viral cough.
Subacute coughs, the ones that linger for three to eight weeks, are often what’s called a post-infectious cough. The infection itself is gone, but your airways haven’t fully recovered. This happens because inflammation takes time to heal, leftover mucus continues to irritate the airways, and the nerves that trigger your cough reflex can stay hypersensitive for weeks after an illness. Post-infectious coughs are frustrating but generally harmless and resolve on their own.
Chronic coughs lasting beyond eight weeks point to something ongoing rather than a single infection. The three most common culprits are postnasal drip, asthma, and acid reflux (GERD). These conditions frequently overlap, and sometimes more than one is responsible.
Postnasal Drip Cough
If you constantly feel like mucus is draining down the back of your throat, you’re probably dealing with postnasal drip. Along with the cough, you may notice frequent throat clearing, a hoarse voice, a sore throat, the sensation of a lump in your throat, or frequent swallowing. Allergies are a common trigger, but sinus infections, pregnancy, certain medications, and acid reflux can all cause it too.
This type of cough tends to be worse when you lie down, making it a frequent cause of nighttime coughing. The mucus that drains easily while you’re upright pools in your throat when you’re flat on your back.
Asthma-Related Cough
Asthma doesn’t always come with obvious wheezing or shortness of breath. A form called cough-variant asthma produces a persistent dry cough as the primary (sometimes only) symptom. This cough often worsens at night, during exercise, in cold air, or around known triggers like dust, pollen, or pet dander. If your cough follows these patterns and tends to be dry and repetitive rather than phlegmy, asthma is a real possibility, even if you’ve never been diagnosed.
Acid Reflux Cough
GERD causes a chronic dry cough when stomach acid irritates the lower esophagus or reaches the throat. You might not even have classic heartburn. Some people with reflux-related cough notice it worsens after meals, when lying down, or after eating acidic or spicy foods. A persistent dry cough with no obvious respiratory cause, especially if you also get a sour taste in your mouth or mild throat irritation, is worth evaluating for reflux.
Medication-Related Cough
If you take medication for high blood pressure, check whether it’s an ACE inhibitor (common names end in “-pril,” like lisinopril or enalapril). These drugs cause a persistent dry, tickly cough in a notable percentage of users. In a study of over 27,000 patients, about 4% developed a cough significant enough to stop the medication. The cough can start within weeks of beginning the drug or develop months later, which makes it easy to miss the connection. Switching to a different type of blood pressure medication resolves it.
What the Cough Sounds Like
Some coughs have very distinctive sounds that point to specific conditions. A harsh, barking cough that sounds like a seal is characteristic of croup, which occurs when the vocal cords and upper airway swell. Croup primarily affects young children and often comes with a high-pitched whistling sound when breathing in. The barking gets worse with crying, anxiety, and more coughing, which creates a cycle that can be alarming for parents.
Whooping cough (pertussis) produces intense coughing fits followed by a sharp, high-pitched “whoop” as the person gasps for air. In adults, the whoop may be absent, but the coughing spells are unusually violent and prolonged, sometimes causing vomiting.
When Timing Is a Clue
Pay attention to when your cough is worst. Nighttime coughing has a specific set of causes: postnasal drip, asthma, and acid reflux all worsen when you’re lying down. But a cough that gets worse at night and keeps you from sleeping can also signal a cardiac cough. Heart failure can cause fluid to pool in the lungs, a condition called pulmonary edema, and your body coughs to try to clear it. This type of cough is typically persistent, may produce frothy or pink-tinged mucus, and comes with other signs like swollen ankles, shortness of breath with exertion, or fatigue.
Morning coughs that produce mucus are common in smokers and people with chronic bronchitis, as overnight mucus accumulation clears when you get up and start moving. Exercise-triggered coughing points toward asthma or exercise-induced bronchospasm.
Signs That Need Prompt Attention
Most coughs resolve without intervention, but certain features warrant a call to your doctor: difficulty breathing, painful or difficult swallowing, coughing up blood or blood-streaked phlegm, wheezing, thick green or yellow phlegm, or a high or persistent fever. A cough lasting more than a week with any of these symptoms should be evaluated rather than waited out.