What causes blood in sputum?

1. Bleeding caused by throat diseases

The throat belongs to the upper respiratory tract, the mucous membrane is relatively fragile and rich in capillaries. When inflammation, foreign body injuries (fish bones, bone spurs, etc.) and pharyngeal tumors (such as nasopharyngeal cancer) occur, the small blood vessels dilate and the permeability of the blood vessel walls increases. Under the stimulation of inflammation and severe coughing, they are prone to rupture and bleed, and are coughed out through the mouth.

Generally, pharyngitis does not bleed easily, and even if it bleeds, the amount is very small. Older people who have blood in their sputum, especially those with nosebleeds, may have nasopharyngeal cancer and must be paid attention to.

2. Bleeding caused by lower respiratory tract diseases

When the vocal cords are closed, the lower respiratory tract is in a closed state, and ruptured blood vessels and bleeding in the airway are mostly caused by lesions. Therefore, hemoptysis often indicates lesions in the trachea, bronchi, lungs, etc. There are three common causes: tuberculosis, bronchiectasis, and lung cancer. In our country, the leading cause is tuberculosis, followed by bronchiectasis and lung cancer. If young people have blood in their sputum and are accompanied by symptoms such as cough, night sweats, and weight loss, tuberculosis is often considered; in the elderly, lung cancer is more likely, especially those with an irritating cough and a long history of smoking. If there is a history of coughing up purulent sputum, bronchiectasis is more common. In addition, pneumonia and bronchitis may also cause blood in sputum. Chronic bronchitis and mycoplasma pneumonia may also cause blood in sputum, but the amount is generally less.

3. Bleeding caused by cardiovascular disease

The cardiovascular system is closely related to the pulmonary circulatory system. When cardiovascular diseases occur, it often causes congestion in the lungs and rupture of bronchial capillaries. It is most common in mitral stenosis, followed by pulmonary hypertension caused by congenital heart disease. Pulmonary embolism, pulmonary vasculitis, hypertension, etc. can also cause blood in sputum or hemoptysis. This type of patient is often accompanied by a long history of cardiovascular disease. The hemoptysis symptoms are small in quantity and mostly in the form of pink foamy sputum. Generally, there is no need to panic, as the disease will disappear once the cardiovascular disease is controlled.

4. Bleeding caused by systemic diseases

Blood system diseases such as leukemia and hemophilia, due to abnormal coagulation function, the airway mucosa is easily ruptured and causes bleeding. There are also some immune diseases such as systemic lupus erythematosus and Wegener's granulomatosis.