Why Is Menstrual Blood Black on the First Day of the Period?

Normal menstrual blood should be dark red. If the blood on the first day of menstruation appears black, it is essential to identify the underlying cause. From the perspective of Traditional Chinese Medicine (TCM), this may be related to deficiency of both Qi and blood. From a Western medical standpoint, it may indicate menstrual irregularities or certain gynecological conditions. Below, we address the question: Why is menstrual blood black on the first day of the period?

Black Menstrual Blood on the First Day of the Period
　　1. Kidney Deficiency: Menstrual blood may appear black, often accompanied by an unstable menstrual cycle and scanty flow. The blood color may be pale red or dark red, with thin consistency. Symptoms include soreness and weakness in the lower back and legs, heel pain, dizziness, tinnitus, and cold sensation in the abdomen.

2. Cold in the Blood: Menstrual blood may also appear black, with delayed periods and reduced volume. The blood color is dark, and there may be cold, painful sensations in the lower abdomen. Warming the lower abdomen provides relief. The tongue coating is white, and the pulse is deep and tight. Treatment focuses on warming the meridians and dispelling cold.
　　3. Deficiency of Both Qi and Blood: This pattern may also cause blackish menstrual blood, along with irregular cycles—either early or late—and variable flow (increased or decreased). Menstruation may last longer than normal, with pale-colored, thin, watery blood. Mild abdominal pain may occur, accompanied by fatigue, spontaneous sweating, pallor or sallow complexion, poor appetite, anorexia, and constipation. The tongue coating is light red, and the pulse is fine and weak. Treatment aims to tonify Qi and nourish blood.
　　4. Qi Stagnation and Blood Stasis: Menstrual blood appears blackish-purple, with unpredictable timing and variable volume. Clots may be present, and menstrual flow may be sluggish or obstructed. There may be distending or stabbing pain in the lower abdomen that worsens upon pressure, or distension and pain in the chest, ribs, breasts, or lower abdomen, along with epigastric fullness and discomfort. The tongue may appear purplish-dark or show petechiae, with a thin white or thin yellow coating; the pulse is wiry or choppy. Treatment emphasizes activating blood circulation, resolving stasis, regulating Qi, and relieving pain.

Additional Information: Recommended Foods During Menstruation

During menstruation, blood loss depletes plasma proteins, iron, potassium, calcium, and other nutrients. Therefore, consuming blood-nourishing foods is especially beneficial. Red bean soup or red bean porridge is highly recommended as a beauty-enhancing food for women during their periods. Drinking brown sugar water regularly during menstruation helps expel stagnant blood, warms the body, boosts energy, and promotes smooth circulation of Qi and blood.

If a woman notices black menstrual blood, she should take it seriously, as it is a typical sign of Qi and blood deficiency. Dietary therapy can effectively improve this condition; incorporating nutrient-rich soups and porridges that replenish Qi and blood is advisable. Although black menstrual blood may not seem serious in the short term, persistent occurrence over time could potentially impair fertility. Hence, women must pay close attention to this symptom.

The above outlines the possible reasons why menstrual blood appears black on the first day of the period. We hope this information is helpful to you.