It may be due to lung disease. If the mucus is yellow or green mucus, it is mostly due to infection but if you do have an infection you will also have other symptoms, such as fever, congestion. If there is large volumes of it, call your doctor. Rule out the cause and treat.
Btw, here are few tips:
- Eat detoxifying food. Include fresh fruit and vegetables which are great for detoxifying. Great detox foods include broccoli, cauliflower, broccoli sprouts, onions, garlic, artichokes, beets, red and green vegetables.
- Reduce the intake of sugary and dairy products.
- Avoid caffeinated and alcohol consumption.
- Avoid food additives and preservatives.