Thick, Sticky Mucus Causes and Treatment

Thick, rubbery mucus in the back of the throat, also known as catarrh, is a symptom that often results from infection in the nasal passages, sinuses, lower airways, or lungs. It may also occur with a range of conditions including the common cold, asthma, sinusitis, pneumonia, and cystic fibrosis.

Symptoms associated with thick mucus include fever, cough, shortness of breath, and fatigue, based on the cause. This article will discuss the symptom of thick, sticky mucus, common causes, when to see a healthcare provider, diagnosis, and treatment.

Symptoms of Thick, Sticky Mucus

In the presence of an infection, allergen, or irritant, your body may make larger amounts of mucus to help trap foreign invaders. But large amounts of mucus can clog the airways in your nose, throat, lungs, and sinuses, making breathing difficult.

It can also cause you to cough. If you have an increased amount of mucus, you may cough up white, green, or brownish sputum.  

Thick sticky mucus is rarely an isolated symptom. It may be associated with the following symptoms based on the cause:

• Fever
• Chills
• Cough (a productive cough is when you make so much sputum that you cough up thick yellowish-green or brown sputum)
• Sneezing
• Congestion
• Headache
• Shortness of breath
• Chest tightness
• Fatigue
• Sore throat
• Difficulty swallowing
• Muscle aches
• Nausea and vomiting
• Loss of appetite
• Rash

Causes of Thick, Sticky Mucus

The body's mucous membranes produce mucus. These membranes line your respiratory tract from your nose to your lungs. They also produce mucus in the digestive, reproductive, and urinary systems.

Mucus is important in ensuring your body tissues don't dry out. It also filters out dust, allergens (substances that may trigger an allergic reaction), and microbes.

While a small increase in mucus production is natural at times, the presence of foreign invaders, like viruses or bacteria, or allergens like pollen can cause the body to overreact and create thick sticky mucus that may clog your throat and nasal passages.

The common cold (a viral infection) and sinus infections (usually viral but may be bacterial or fungal) are common reasons your body may make thicker mucus.

But a host of conditions can cause your body to produce thick, sticky mucus, including:

• Allergies (pollen, dust, animal dander, allergic fungal rhinosinusitis): Mucus in nose, throat, and/or postnasal drip
• Asthma: A chronic condition of airways that are inflamed and constricted by various triggers, in which more mucus is produced and mucus plugs may develop
• Bronchitis: Inflammation of the larger airways
• Pneumonia: Bacterial or viral lung infection, may cough up green, yellow, or bloody mucus
• Chronic obstructive pulmonary disease (COPD): Progressive inflammatory disease of the lungs, including chronic bronchitis and emphysema
• Bronchiectasis: Permanent widening of the airways, leading to problems clearing mucus
• Lung cancer: Cough and coughing up blood or rust-colored sputum
• Smoker's cough: From chronic smoking, may cough up black or brown mucus
• Cystic fibrosis: An inherited condition that leads to thick mucus production in the lungs and other organs
• Amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease): A progressive disease that attacks the nerve cells that control muscles
  

How to Treat Thick, Sticky Mucus

Treating thick, sticky mucus depends on the cause of your symptoms.

• Viral infections: Most cases of thick mucus are due to respiratory viral infections that are self-limiting (resolve on their own). Treating your symptoms (with advice from a healthcare provider) with over-the-counter (OTC) medications such as pain relievers, decongestants, and expectorants may help you feel better. OTC cough and cold medicines should not be used for children under age 4.
• Bacterial infections: If the cause of your mucus is a bacterial infection (such as in some cases of sinusitis, bronchitis, or pneumonia), your healthcare provider may prescribe a course of antibiotics in mild and moderate cases. More severe cases may need intravenous (IV) antibiotics that are administered at a hospital.
• Allergies: Using antihistamines and washing your bedding regularly can alleviate symptoms caused by allergies to pollen, dust mites, and other allergens.

Sleeping in the propped-up position may help you to breathe better at night and alleviate your coughing symptoms. Using a humidifier may also help.

If you have a rare condition such as cystic fibrosis or ALS, you may develop thick secretions that impact your ability to breathe and swallow. Adequate hydration, coughing exercises, and a portable suction unit may help alleviate your symptoms. 

Complications and Risk Factors Associated With Thick, Sticky Mucus

If you have a bacterial infection and are prescribed antibiotics, it is important to complete the full course of antibiotics and not stop early. This helps ensure all of the bacteria are eliminated so you don't have a resurgence of the infection, which can result in worse symptoms and thick mucus.

Many conditions that cause thick mucus are risk factors for pneumonia, which can be serious or life-threatening. These include asthma, bronchiectasis, cystic fibrosis, and COPD. People who are more at risk for pneumonia include those age 2 or younger or age 65 or older, and those who have a weakened immune system, smoke cigarettes, are hospitalized, or have a serious condition.

Are There Tests to Diagnose the Cause of Thick, Sticky Mucus?

For mild to moderate symptoms, you can use a thermometer at home to see if you have a fever. If you have a fever for longer than five days, you should check with a healthcare provider.

A diagnosis of the cause of your thick sticky mucus starts with a healthcare provider taking a detailed history of your symptoms and performing a physical exam.

The exam includes taking your vital signs (heart rate, breathing rate, temperature, and blood pressure), listening to your heart and lungs, checking for swollen lymph nodes, and performing a focused head and neck exam, looking for signs of infection. 

To determine what might be causing your thick, sticky mucus, your healthcare provider may recommend/perform other tests:

• Chest X-ray (CXR): A CXR is a relatively quick and accessible imaging tool used to detect the presence of fluid in the lungs. 
• Complete blood cell count (CBC): A CBC measures the amount of red, white, and platelet cells in the blood. Higher numbers of white blood cells (immune cells) may suggest a viral or bacterial infection. The presence of fluid in the lungs on CXR and high white blood cell counts on CBC may indicate the need for a sputum culture.
• Sputum culture: A sputum culture is a laboratory test that checks for bacteria-causing infections in the respiratory tract. It is frequently used in the diagnosis of pneumonia, tuberculosis, and bronchiectasis.
  

When to See a Healthcare Provider 

If your symptoms were initially those of a common cold and they last for 10 days or more, get better and then worsen, or you have other health conditions that worsen, contact a healthcare provider.

Symptoms that warrant immediate medical attention include:

• Lung pain
• Gasping for air or having trouble catching your breath
• A raspy, “whooping” noise when you cough
• A high fever (over 103 F)
• Blood in your mucus

Preventing Thick Mucus

While you can't always prevent infections or other health conditions, you can take some measures that may reduce the chances of producing thick mucus:

• Quit smoking: Smoking cigarettes and vaping can make mucus stickier. Quitting smoking can also lower your risk of respiratory problems in general.
• Use a humidifier: Humidifiers add moisture to the air and can help break up mucus.
• Stay well-hydrated: Water can help loosen phlegm and prevent it from becoming too thick. Staying hydrated is also important if you have a respiratory infection, especially with a fever.
• Wear a mask: If you tend to develop thick mucus in response to pollution, allergens, or other environmental irritants, a respirator mask can help filter out irritating particles.
  

Summary

Viral and bacterial infections are two common causes of thick sticky mucus, which can clog your airways, causing you to cough. Viral respiratory illnesses usually resolve on their own. OTC medications, like decongestants and expectorants, may provide relief from symptoms.

If your symptoms of thick mucus last for more than 10 days, contact a healthcare provider for advice, diagnosis, and treatment.

A Word From Verywell

In addition to colds, a variety of illnesses, such as allergies, chronic rhinosinusitis, and even hormonal fluctuations, can result in thick, sticky mucus. If you encounter these symptoms, staying properly hydrated, trying saline nasal irrigation or steam inhalation, and sleeping with the head raised can encourage drainage. Although OTC expectorants can be helpful, you should exercise caution when using them. Seek medical attention if your symptoms intensify, last longer, or involve fever, face pain, or breathing difficulties.

— KASHIF J. PIRACHA, MD, MEDICAL EXPERT BOARD