The phrase "spit up blood" can be distressing for anyone who experiences it. However, there are several synonyms that describe this symptom. Hemoptysis is one such term, meaning coughing up blood from the respiratory tract. Sputum that contains blood is called hemoptoic sputum. Another synonym for spitting up blood is phlegm with blood. Blood-streaked sputum or bloody mucus can also accurately describe this health issue. Additionally, the term "bleeding from the lungs" can be used to describe the underlying cause of spitting up blood and should prompt immediate medical attention. It's important to know these synonyms and seek medical help promptly if you experience any of these symptoms.