What is bhlegm?
The terms mucus and phlegm are often used interchangeably but they don’t refer to the same thing. Mucus is one of the most important secretions produced by the body, as it helps lubricate the areas where it is produced, such as the mouth, sinuses, lungs, stomach, and intestines. As we are discussing phlegm in this article, we will focus more on the mucus produced in the lungs which we can refer to as airway mucus.
Airway mucus is a sticky substance produced by the lungs. It has the primary function of trapping dirt and other materials that are inhaled and removing them from the lungs through coughing, mostly.1 Sometimes, when a person has an allergy or an infection, the mucus that is produced by the lungs becomes thicker, this is referred to as phlegm or sputum.
Common causes of phlegm
Airway mucus is very useful, as it helps to lubricate the respiratory system and trap dust or other materials that can harm the lungs. Phlegm, on the other hand, is a mixture of the mucus, your infection-fighting white blood cells, and the virus or bacteria that is responsible for the infection.
You do not need to have a life-threatening condition like chronic bronchitis, cystic fibrosis, lung cancer, or pulmonary embolism for phlegm to be produced but they can be responsible for phlegm production as well.
The production of phlegm can be caused by a variety of things, which include:
- Allergies: Respiratory allergies cause the body to produce more mucus in an attempt to remove the allergens from the respiratory tract. This can result in phlegm production and breathing difficulties.
- Asthma: Asthma is an inflammatory disease of the respiratory system that causes the airways to narrow and constrict, making breathing difficult. This can result in an increase in phlegm production to protect the lungs from damage
- Sinusitis: Sinus infections or inflammation can cause increased mucus production. This mucus may drain down the back of the throat. Postnasal drip is another term for this
- Smoking: Cigarette smoke irritates the lining of the lungs and causes excess phlegm production
What is the meaning of blood in my phlegm?
Blood in the phlegm is referred to as Haemoptysis.2 Sometimes, phlegm might not be entirely yellow or green and may have traces of blood, that looks like the colour of rust, in it. This should not be mistaken for vomiting blood.
Blood in the sputum may be an indication of a variety of conditions.
Causes of blood in the phlegm
Acute bronchitis
This is the most common and least serious of all the possible reasons why you could have blood in your sputum. Acute bronchitis is a viral infection, often caused by influenza, which simply refers to an inflammation of the bronchi. It is very common and most cases of acute bronchitis often resolve on their own. However, sometimes, when a person has acute bronchitis, the phlegm produced may have blood in it.
Chronic bronchitis
Chronic bronchitis is defined as a productive cough lasting more than three months. It is a type of chronic obstructive pulmonary disease (COPD), which usually develops over a period of two years. There are several reasons why a person may develop chronic bronchitis, but the most common reason is exposure to cigarette smoke - whether through active or passive smoking. Exposure to respiratory irritants, such as smog, industrial pollutants, and toxic chemicals, can also lead to chronic bronchitis.3Symptoms of chronic bronchitis include chronic productive cough, blood in phlegm, chest pain, and abdominal pain.
Bronchiectasis
According to the American Lung Association, bronchiectasis occurs when the size of the bronchi changes, as a result of infection. The bronchi are the two main passages through which air gets into and out of the lungs. When people have bronchitis, their lungs find it more difficult to move air in and out. This eventually leads to an unhealthy buildup of fluid and makes the lungs work overtime to produce oxygen for the body. Bronchiectasis causes the thickening of the blood vessels in the lungs, which can result in bloody phlegm.
Symptoms of bronchiectasis include a chronic cough (a cough that has lasted longer than eight weeks for adults and four weeks for children), shortness of breath, frequent pneumonia, and bloody sputum.
Tuberculosis (TB)
Tuberculosis is a bacterial infection that primarily affects the lungs and if left untreated can affect the gastrointestinal system, the central nervous system, and almost the entire body. TB often affects people who have conditions that make their immune system weak, like people living with Human Immunodeficiency Virus (HIV), and children. According to the World Health Organization, TB was responsible for 1,000,000 illnesses in children in 2015.4 If not treated properly, tuberculosis can cause a rupture of blood vessels in the lungs or other scarring that will result in bloody phlegm, which can be life-threatening.4The symptoms of tuberculosis include fever, night sweats, cough, weight loss, tiredness, chest pain, and coughing up blood.
Cancer
Cancers of the airway or lungs have the potential to cause bleeding. Cancers that affect the respiratory system can be lung cancer, but can also be cancers that have spread from another organ. Lung cancer is not very common, according to data collected by the American Lung Association. Of all the patients that are diagnosed with cancer each year, only about 3% of cases are lung cancer. However, compared to other cancers, the chances of survival for any patient diagnosed with lung cancer are not very great. The symptoms of lung cancer are similar to tuberculosis, such as shortness of breath, blood in phlegm, weight loss, fever, night sweats, and chest and abdominal pain.
Is it common to have blood in phlegm?
Seeing blood in phlegm can be frightening but in most cases, it is nothing to worry about. Coughing sometimes puts a strain on the throat and lungs, which may cause some injury to the blood vessels there. A study conducted in the United States, showed that haemoptysis is common in 23% of patients who have bronchiectasis.5
When should I worry?
If you notice blood in your phlegm, you may want to seek medical advice if:6
- Your sputum has a lot of blood in it
- You have difficulty breathing
- You experience any symptoms that suggest you are losing blood, such as weakness, dizziness when standing up, thirst, sweating, and a rapid heart rate
- You feel very weak or exhausted
In addition, hemoptysis is more common in older people, aged 60 years and above, so you may not necessarily be concerned if you are still much younger.7 Your medical history is also very important. If you have asthma, bronchitis, or any other respiratory condition, please see your doctor.
Prevention and treatment
The NHS recommends that people who smoke should quit smoking to prevent the development of any condition that can cause hemoptysis. Keeping yourself hydrated and excercising regularly also help.
When to see a doctor
Blood in the phlegm may not mean that anything serious is wrong with you but it may also be a sign of something serious. Whatever the case may be, please check with your general practitioner or doctor before you make any decisions.
Summary
Having bloody phlegm or sputum is fairly common when a person has a respiratory disease. It can be very frightening to find blood in your sputum but it may not mean that there is anything wrong with you. However, because of the serious conditions that are associated with bloody phlegm, please monitor your phlegm and see a doctor or your GP if you notice any change in colour.
References
- Fahy JV, Dickey BF. Airway mucus function and dysfunction. New England Journal of Medicine [Internet]. 2010 Dec 2 [cited 2022 Sep 29];363(23):2233–47. Available from: https://doi.org/10.1056/NEJMra0910061
- Corey R. Hemoptysis. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations [Internet]. 3rd ed. Boston: Butterworths; 1990 [cited 2022 Sep 29]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK360/
- Widysanto A, Mathew G. Chronic bronchitis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Sep 29]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK482437/
- Adigun R, Singh R. Tuberculosis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Sep 29]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK441916/
- Lim RK, Tremblay A, Lu S, Somayaji R. Evaluating hemoptysis hospitalizations among patients with bronchiectasis in the United States: a population-based cohort study. BMC Pulmonary Medicine [Internet]. 2021 Dec 1 [cited 2022 Sep 29];21(1):392. Available from: https://doi.org/10.1186/s12890-021-01762-6
- Coughing up blood - lung and airway disorders [Internet]. MSD Manual Consumer Version. [cited 2022 Sep 29]. Available from: https://www.msdmanuals.com/home/lung-and-airway-disorders/symptoms-of-lung-disorders/coughing-up-blood
- Bidwell JL, Pachner RW. Hemoptysis: diagnosis and management. afp [Internet]. 2005 Oct 1 [cited 2022 Sep 29];72(7):1253–60. Available from: https://www.aafp.org/pubs/afp/issues/2005/1001/p1253.html