What Are Common Causes of Green Mucus?

Green mucus typically indicates the presence of an infection, whether viral or bacterial. It is a sign that the body's immune system is fighting off a bacterium or virus, often resulting in an upper respiratory tract infection (URTI). The common cold is one of the most common URTIs that leads to green mucus. Some patients develop sinusitis after a cold, which can result in the continuation of greenish mucus in the sinuses as the result of inflamed membranes. Other URTIs, including tonsillitis and rhinitis, also can result in mucus of this color in the throat and sinuses.

One of the most common causes of green mucus is the common cold, which originates from a virus. The symptoms usually include a runny nose, frequent sneezing and a sore throat. The green mucus often comes from both the nose and the throat, because a cough that produces discharge is common. Antibiotics do not fight viruses, so the typical treatment for a cold is lots of liquids, such as water and soup, along with a lot of rest. The symptoms can be treated with saline sprays to relieve congestion, and by gargling salt water to soothe a sore throat.

Sometimes a cold seems to be resolved, only to be followed by sinusitis, which occurs when the nasal membranes are irritated by an infection. Other than green mucus, symptoms include a cough, fatigue and frequent headaches. Many patients find it difficult to breathe because of nasal congestion and also cannot smell or taste food very well, often leading to loss of appetite. Pressure in the face, teeth and ears is another symptom of sinusitis. Home remedies for this condition include hydration, rest and acetaminophen to relieve facial pressure; doctors often prescribe amoxicillin to kill any bacteria in the sinus membranes.

Other upper respiratory tract infections that result in green discharge include an infection in the pharynx, larynx, sinuses or all of these. For example, tonsillitis is an infection of the tonsils, causing the tissue to become red and dotted with pus that is white, yellow or green. Rhinitis, on the other hand, describes a stuffy nose that is caused by either allergens or a virus. It is often characterized by congestion, green mucus in the nose and swollen eyelids. Avoiding allergens is usually the best way to treat rhinitis caused by allergies, while nasal sprays and decongestants are best for cases caused by viruses.