Most people would think of mucus as being a hindrance and a problem rather than a useful substance. The truth is that it can be both. In a healthy state, our bodies produce mucus to assist with various body functions.
For example, mucus is in our respiratory system and prevents dust particles and other pollutants like cigarette smoke from entering our lungs. It lubricates our airways â€“ including our throat and nasal passages.
In our digestive system, mucus helps us to swallow food and eases the passage of food through our digestive tract. The stomach lining is coated with mucus to protect it from being damaged by our stomach acid. And in our reproductive system, mucus is there for lubrication purposes.
When we are healthy, our mucus is clear and colorless. It is the consistency of thin jelly. However, when we have an infection or are ill, our mucus can become darker and be yellow or green in color. When we cough up infected mucus, this is what is phlegm or sputum. Infected mucus is thicker and gathers in our airways and on our chests â€“ it adds to the feeling of congestion that you have when you have a cold.
You can find out advice on green mucus at Mucus Management, a website that provides information and advice on the causes of excess mucus production.
If you have noticed that your mucus production levels have increased and that your mucus is thicker and darker in colour than normal, you should monitor this as it can be an indicator of a more serious illness.
Excess mucus is a symptom that has been linked to allergies, asthma, cancer and cystic fibrosis. Most people with a head cold will have excess mucus for a short period while they have the cold, but if it remains for a long period and doesnâ€™t reduce you should seek medical advice.