<s>[INST] My husband threw up thick black vomit. Any idea what this could be? [/INST] hello, it  usually caused by bleeding in the upper gastrointestinal tract . the reasons for bleeds can include prolonged vomiting leading to tears in the esophagus, tumors, alcoholism, a ruptured ulcer, internal trauma, and hemorrhagic diseases like yellow fever.consult your doctor about it.dont negelect. </s>