Wet cough vs dry cough: what the difference tells you

A cough is a reflex that clears the airways of phlegm and irritants such as dust or smoke, according to NHS inform. It describes it as rarely a sign of anything serious. In everyday use coughs are divided by whether anything comes up.

A dry cough is tickly and does not bring up mucus. A wet or chesty cough produces phlegm, which NHS inform says helps to clear the airways. This split is not a diagnosis, but it gives you a plain way to describe the cough to a pharmacist or GP.

The table below is built from what the NHS and NHS inform say about coughs, chest infections and bronchitis.

The NHS says most coughs are caused by a cold or flu. Other causes include smoking, heartburn (acid reflux), allergies such as hay fever, infections like bronchitis or COVID-19, and mucus dripping down the throat from the back of the nose. It adds that a cough is rarely a sign of something serious such as lung cancer.

NHS inform separates short-term and persistent coughs. For short-term coughs it lists upper respiratory tract infections such as colds, flu, laryngitis, sinusitis or whooping cough, lower respiratory tract infections such as acute bronchitis or pneumonia, allergies, flare-ups of long-term conditions such as asthma, COPD or bronchiectasis, and breathing in dust or smoke.

For persistent coughs it lists asthma (which usually causes other symptoms such as wheezing, chest tightness and shortness of breath), allergy, smoking, bronchiectasis, gastro-oesophageal reflux disease (GORD) and some prescribed medicines such as ACE inhibitors used for high blood pressure, with ramipril and lisinopril given as examples. Often the cause of a persistent cough is unknown. It also says that rarely a persistent cough can be a symptom of a more serious condition such as lung cancer, heart failure, a pulmonary embolism or tuberculosis.

The NHS chest infection and bronchitis pages describe a chesty cough as part of those illnesses. The NHS says that chest infections often follow colds or flu, and that the main symptoms include a chesty cough where you may cough up green or yellow mucus, wheezing and shortness of breath, chest pain or discomfort, a high temperature, a headache, aching muscles and tiredness. Symptoms usually get better on their own in about 7 to 10 days, though the cough and mucus can last up to 3 weeks.

Whether a chest infection needs treatment depends on its cause. The NHS says a viral infection, such as viral bronchitis, usually clears up by itself after a few weeks and antibiotics will not help, whereas bacterial infections such as pneumonia may need antibiotics prescribed by a GP. You may need a blood test or a sample of mucus tested to see what is causing it.

The NHS bronchitis page describes bronchitis as inflammation of the airways that is usually caused by an infection and that often gets better without treatment in around 3 weeks, with a cough that may bring up mucus. It notes that some people have long-term inflammation of the airways, called chronic bronchitis, which is known as chronic obstructive pulmonary disease (COPD).

NHS inform says that in most cases a doctor will need to know if you are producing much more or darker phlegm than usual.

NHS inform lists asthma, allergy, smoking, reflux and certain medicines among the causes of a persistent cough, and says that if your cough has a specific cause, treating it may help: inhaled steroids for asthma, avoiding triggers and taking antihistamines for allergies, and antacids or acid-reducing medicine for reflux.

The NHS and NHS inform are cautious about cough medicines. The NHS says a pharmacist can help with cough syrup, cough medicine and cough sweets, which will not stop the cough but may help you cough less, and that decongestants and cough medicines containing codeine will not stop your cough. NHS inform says there is no evidence that cough medicines work, that over-the-counter cough and cold medicines should not be given to children under 6, and that a homemade honey and lemon remedy is likely to be just as useful and safer. Honey should not be given to babies under 1 year. The NHS adds that there is limited evidence that hot lemon and honey and herbal medicines help.

The NHS says to see a GP if you have had a cough for more than 3 weeks, you are losing weight for no reason, or you have a weakened immune system, for example because of chemotherapy or diabetes. It says to ask for an urgent GP appointment or get help from NHS 111 if your cough is very bad or quickly gets worse, you feel very unwell, have chest pain, find it hard to breathe, are coughing up blood, or the side of your neck feels swollen and painful.

NHS inform lists the emergency signs: phone 999 or go to A&E for severe difficulty breathing, severe chest pain in the middle of the chest that is not going away, pain that spreads to arms, back, neck or jaw, feeling more drowsy than usual or finding it more difficult to wake, or lips or skin turning very pale, blue or grey.

At the appointment, the NHS says a GP might listen to your chest with a stethoscope, take a sample of any mucus, or order an X-ray, allergy test or lung function test, and refer you to hospital only rarely. The NHS bronchitis page separately lists being over 65, being pregnant and having a long-term heart, lung or kidney condition among reasons to ask for an urgent appointment or NHS 111 help.