What is the cause of coughing up blood and sputum? There are 5 reasons

Coughing up blood and sputum is a condition that many people experience in daily life, but most people do not know what causes coughing up blood and sputum, so they often miss the best time for treatment. So what is the cause of coughing up blood and sputum? Let's take a closer look!

Most respiratory diseases are accompanied by symptoms of cough and sputum. Sputum can be grayish white mucus or yellow-green purulent sputum. Sometimes the coughed-up sputum contains bright red blood, which is called hemoptysis. In medicine, bleeding from the trachea, bronchi or lung tissue below the larynx that is coughed out of the body is called hemoptysis.

The main mechanisms of hemoptysis are as follows:

1. Increased vascular permeability

Due to lung infection, poisoning or vascular embolism, pathogens and other metabolic products can directly damage the microvessels or increase the permeability of the microvessel walls through the action of vasoactive substances. Red blood cells enter the alveoli from the gaps between the dilated microvascular endothelial cells and cause a small amount of hemoptysis.

2. Erosion and rupture of blood vessel walls

Chronic lung infection damages the elastic fibers of the blood vessel walls, causing local formation of small artery hemangiomas. During severe coughing or movement, the hemangiomas rupture and bleed profusely, often causing suffocation and sudden death. This type of hemangioma is more common in cavitary pulmonary tuberculosis.

3. Increased pressure in the pulmonary blood vessels. In cases of rheumatic heart disease, valvular stenosis, pulmonary hypertension, hypertensive heart disease, etc., increased pressure in the pulmonary blood vessels can cause blood extravasation or rupture of small blood vessels, leading to hemoptysis.

4. Disorders of blood coagulation function are common in blood diseases such as thrombocytopenic purpura, which are caused by coagulation factor defects or coagulation process disorders and poor vasoconstriction.

Hemoptysis may also occur.

5. Mechanical damage to blood vessels caused by trauma or calcification of tuberculosis, or bronchial stones can cause hemoptysis.