Nothing is sure to bring up imagines of your immediate death more than coughing up blood. Although this symptom is frightening, there are many explanations for coughing up blood, ranging from the dire to the less life-threatening.

Severe Cough

According to the National Health Service of the United Kingdom, coughing up blood, or hemoptysis as it is medically known, is rarely a sign of a serious health problem. The usual culprit of bloody sputum is a severe cough, such as those associated with bronchitis or a chest infection. In these cases, the symptom is not life-threatening and simply a side effect of swollen and overworked airways. Chest infections can be caused by either a virus or a bacteria, and usually clear up on their own. Although anyone can contract a chest infection, the very young and old, as well as those who are already ill or who smoke, are at most risk. If a chest infection is at the root of your bloody phlegm, you may notice that the phlegm is also mixed with pus.


Along with its many unhealthy side effects, excessive smoking can also cause you to cough up blood. According to New Health Advisor, this is because smoking can damage the tissues in your respiratory system. The symptom usually clears up once you give up smoking.

High Altitude

High altitude may be another explanation for a sudden red-colored cough. The higher the altitude, the less oxygen and air pressure there is in the atmosphere. As a result, your body may have trouble adapting to the sudden change in environment, and especially those who also exert themselves in higher altitudes, such as hikers and skiers, may feel the effects of something known as acute mountain sickness, Healthline reported.

In addition to causing you to cough up blood, acute mountain sickness can also cause symptoms such as: shortness of breath, chest tightness, and inability to walk in a straight line or to walk at all. According to Medlineplus, mild cases of the condition can usually be remedied by reducing physical activity and returning to a lower altitude, but more serious cases may need hospitalization.

Medications And Drugs

Coughing up blood can also be a side effect of blood thinner medications which work to prevent your blood for clotting up or coagulating, and as a result may cause excessive bleeding. Although, once again, coughing blood while on blood thinners is not an immediate sign of danger, it should not be brushed off and patients are advised to inform their doctors at the first sign of this symptom, Everyday Health reported.

Many illegal drugs, especially those which are snorted, smoked or inhaled, such as crack cocaine, can also cause blood spit, New Health Advisor reported. This is because these drugs can damage the respiratory system, making it more likely to bleed.

Lung Cancer

Coughing up blood is one of the more recognizable signs of lung cancer. This bleeding is usually caused when the small blood vessels in your lungs break up due to a tumor, although tumor death can also cause bloody coughs. However, in the case of lung cancer, bloody coughs are usually experienced alongside other cancer symptoms such as poor appetites, unexplained weight loss, and severe chest pain, and is more common in individuals aged 40 and over.