hemoptysis
Meaning of hemoptysis: In heavy bleeding it is the flooding of the airways, not the volume of blood lost, that does the damage.
Definition of hemoptysis
Hemoptysis is the coughing up of blood, or of mucus streaked with blood, that has come from the lungs or the airways. The amount ranges from a few flecks in sputum to a large volume. The term is defined by the source rather than the quantity, which is why separating it from blood arriving from the nose, mouth or stomach matters.
How is it told apart from vomited blood?
| Coughed from the airway | Vomited from the digestive tract | |
|---|---|---|
| Color | Bright red, often frothy | Darker red or brown, like coffee grounds |
| Mixed with | Sputum, sometimes bubbles of air | Food, gastric contents |
| Preceded by | Coughing, a tickle or gurgle in the chest | Nausea, retching, upper abdominal discomfort |
| Acidity | Neutral or alkaline | Acidic |
Blood from a nosebleed running backward, or from bleeding gums, can be coughed out later and imitate either pattern, which is why the mouth and nose are examined as well as the chest.
What causes it?
Infection and inflammation of the airways account for most cases, including bronchitis, pneumonia and tuberculosis. Bronchiectasis, in which airways are permanently widened and scarred, bleeds repeatedly because the blood vessels along those damaged walls enlarge over time. A tumor growing in or near an airway can erode a vessel, and hemoptysis is one of the ways that small cell lung cancer and other lung tumors first announce themselves. A clot in the lung circulation, an abnormal tangle of vessels, certain forms of inflammation of small vessels, mitral valve disease and blood thinning medication make up much of the remainder.
Why does the volume change the picture?
Small amounts are usually a clue rather than a threat. Large volume bleeding is different in kind, because the airways hold only a small volume before gas exchange fails. The danger is drowning rather than blood loss, and that is what makes it an emergency at volumes far below those that would matter elsewhere in the body. Most heavy bleeding comes from the bronchial arteries, which carry blood at the same pressure as the rest of the body, rather than from the low pressure pulmonary circulation. Evaluation typically pairs chest imaging with direct inspection of the airways to find where the blood is coming from.
Used in a sentence
The patient's report of hemoptysis prompted chest imaging to identify the source of bleeding.
Good to know
Hemoptysis is distinguished from blood that originates in the nose or digestive tract and is later coughed up, since the true source changes the range of likely causes entirely.
Word origin
Where “hemoptysis” comes from
Formed from haima, Greek for blood, and ptysis, meaning a spitting.