What are the reasons for less menstrual flow and a longer duration?

Patient's question:

Detailed medical condition and consultation purpose: Cause
Duration and persistence of this illness: 5 days
Current general condition: It was already over 3 days ago
Medical history:
Previous diagnoses, treatments, and their effectiveness:

Doctor's answer:

There are two main categories of factors that affect menstruation:
1. Disorders of the nervous-endocrine function: This is primarily due to defects in the hypothalamic-pituitary-ovarian axis endocrine system, which manifests as menstrual irregularities due to endocrine disorders.
2. Organic lesions or drug-induced causes: This includes local inflammation, tumors, and developmental abnormalities of the reproductive organs, as well as malnutrition. The occurrence of menstrual irregularities not only affects a woman's physical health but can also lead to gynecological diseases. Therefore, it is best to undergo a vaginal discharge examination at the gynecology department of a hospital to identify the underlying cause and receive targeted treatment. Additionally, dietary adjustments should be made, focusing on light and easily digestible foods, while avoiding spicy, irritating, and cold foods.