What is sputum?

Sputum is produced when a person's lungs are diseased or damaged. Sputum is not saliva but the thick mucus - sometimes called phlegm - which is coughed up from the lungs.

The body produces mucus to keep the thin, delicate tissues of the respiratory tract moist so that small particles of foreign matter that may pose a threat can be trapped and forced out.

Sometimes, such as when there is an infection in the lungs, an excess of mucus is produced. The body attempts to get rid of this excess by coughing it up as sputum.

Causes and colors

There are many different reasons for the body to produce excess sputum. Below is a list of some of these causes, along with how the sputum may appear.

Smoking

In smokers, mucus builds up in the lungs, causing a "smoker's cough." The sputum produced may be green, yellow, or bloody.

Asthma

People with asthma have airways that are sensitive to allergens, environmental pollution, and respiratory infections. This sensitivity can lead to the airways becoming inflamed, as well as an increase in mucus production.

Cystic fibrosis

Cystic fibrosis is an inherited disease caused by a defective gene. It leads to smaller airways becoming blocked by thick mucus, which causes breathing difficulties.

The thick mucus in cystic fibrosis becomes an ideal environment for bacteria to grow. Many people with cystic fibrosis develop chronic bacterial lung infections.

Respiratory tract infections (RTI)

Sputum that is a different color from saliva may be a sign of a lower RTI. With bacterial RTIs, sputum may also have a thick consistency and an unpleasant odor.

As a general rule, sputum is dark green in the early stages of an infection and gradually lightens as the infection improves. It is the presence of an enzyme called myeloperoxidase that gives the sputum its green color, during an infection.

Some infections may cause sputum to be yellow, gray, or rusty colored.

Common RTIs

Flu

Flu, or influenza, may result in green phlegm. The main symptoms are:

·         high temperature, of 100.4°F or above

·         tiredness

·         weakness

·         headache

Other common symptoms include general aches and pains, a chesty cough, and cold-like symptoms, such as a blocked or runny nose, sneezing, and a sore throat.

People should rest at home, drink plenty of water, and keep warm. Over-the-counter painkillers will help when someone has the flu, and most people will start to feel better within a week.

If started within 2 days of becoming ill, antiviral drugs such as oseltamivir can lessen the time someone is sick by 1-2 days. Taking antiviral drugs later in the infection can also be beneficial, particularly if someone is very ill or has a high risk of developing complications.

 Source: Medical News Today