What does melena indicate?

Melena refers specifically to dark, sticky feces that typically result from the presence of partly digested blood. This condition often indicates bleeding that has occurred in the upper gastrointestinal tract, such as the stomach or duodenum, allowing blood to be partially digested as it moves through the intestines. The dark color and tarry consistency is due to the breakdown of hemoglobin, which occurs as blood is digested, and this appearance is a key factor in identifying melena in a clinical setting. Recognizing melena is important for healthcare providers as it can signal significant gastrointestinal bleeding, which may require urgent medical attention.

In contrast, the other options refer to different medical signs: the presence of blood in urine pertains to hematuria, coughing up blood is known as hemoptysis, and the mixture of saliva and mucus from the respiratory tract relates to sputum. Each of these terms describes distinct clinical symptoms that arise from various health issues, unrelated to the condition defined by melena.