What are the causes of black menstrual blood?

Generally, black menstrual blood may be caused by prolonged retention of menstrual blood in the uterus, poor diet and lifestyle habits, high mental stress, endometritis, or endometriosis. If discomfort occurs, it is advisable to seek medical attention promptly. Detailed explanations are as follows:

1. Prolonged Retention of Menstrual Blood in the Uterus

When menstrual blood flows slowly and remains in the uterus for an extended period, iron ions in the blood become oxidized, causing the menstrual fluid to darken or even turn black. Engaging in moderate exercise helps promote blood circulation. Avoid prolonged sitting or lying down during menstruation to facilitate the smooth discharge of menstrual blood.

2. Poor Diet and Lifestyle Habits

Excessive consumption of cold foods, lack of physical activity, and irregular sleep patterns can all impair the body’s circulation of qi and blood, leading to poor menstrual flow and darker, even black, menstrual blood. It is recommended to adjust dietary habits by reducing intake of cold foods and increasing warm-nourishing foods such as red dates and longan.

3. High Mental Stress

Psychological stress can disrupt hormonal balance and interfere with the endocrine system, affecting normal shedding of the endometrium and menstrual discharge, which may result in dark or black menstrual blood. Learning stress management techniques, maintaining a positive and optimistic mindset, and increasing outdoor activities and fresh air exposure can help.

4. Endometritis

Endometritis is an inflammation of the endometrium caused by bacterial infection, which damages the uterine lining and affects menstrual discharge, often resulting in dark or black blood. Symptoms may include lower abdominal pain, fever, and increased vaginal discharge. Treatment under medical guidance may include medications such as metronidazole tablets, cefradine capsules, and Gynecological Qianjin tablets.

5. Endometriosis

Endometriosis, caused by factors such as genetics or immune abnormalities, involves the growth of endometrial tissue outside the uterine cavity, leading to cyclic bleeding and pain. Bleeding from ectopic endometrial tissue may mix with menstrual blood, causing it to appear dark or black. Symptoms may also include dysmenorrhea (painful periods) and infertility. Patients are advised to follow medical instructions for symptom relief using medications such as danazol capsules, gestrinone capsules, or Guizhi Fuling pills.

In daily life, it is important to stay warm, avoid raw and cold foods, maintain a balanced diet, adhere to regular作息 (sleep-wake cycles), and engage in moderate exercise to support overall health and prevent issues such as abnormally dark menstrual blood.