Why is my menstrual blood black and scanty?

Women experience menstruation each month. Normal menstrual blood is typically dark purple or red, with a typical monthly volume ranging from 20 to 60 mL. So why does menstrual blood sometimes appear black and scanty?

Why Is Menstrual Blood Black and Scanty?

Normally, menstrual blood is red. When it appears black, this warrants attention. Menstrual blood contains fragments of endometrial tissue, cervical mucus, and vaginal epithelial cells, which collectively impart a darker hue—less bright than fresh blood resulting directly from endometrial injury. These small, thin tissue fragments contribute to the darker appearance. Black, scanty menstrual flow may indicate prolonged retention of blood within the uterine cavity or underlying gynecological inflammation, suggesting impaired uterine function. In women who have not yet given birth, such abnormalities may adversely affect future fertility; therefore, prompt evaluation and treatment at a reputable hospital are recommended.

Black, scanty menstrual flow is commonly associated with patterns such as “cold congealing and blood stasis” or “qi stagnation and blood stasis,” leading to impaired circulation in the meridians and hindering normal expulsion of menstrual blood. It is often accompanied by symptoms including abdominal pain and passage of clots. Clinically, this presentation is frequently linked to conditions such as endometritis, abnormally thin endometrium, or endocrine imbalance. Symptomatic management may include herbal preparations such as Yimucao Granules (Leonurus japonicus granules) or warm ginger–brown sugar water, followed by careful observation.

If symptoms persist or fail to improve with conservative measures, further diagnostic evaluation—including sex hormone panel (six-item hormonal assay), gynecological ultrasound, and comprehensive clinical assessment—is warranted to establish an accurate diagnosis. We hope this information has been helpful to you!