When you have an infection, your immune system’s white blood cells rush to the ... or discolouration from inhaling smoke. If you’re coughing up brown mucus, though, you should see a doctor ...

Throwing up mucus can occur when mucus from your stomach lining or mucus that you swallow appears in your vomit. Mucus from postnasal drip and coughing can also trigger vomiting, especially in ...