What's wrong with not having a menstrual period for several months?

Patient's question:

Detailed medical condition and consultation purpose: Irregular menstruation, concerned
Duration of current illness and persistence: For 3-4 months, missed two periods. Tried Chinese medicine regulation during the May Day holiday, which was normal for 3-4 months, then returned to irregularity.
Current general condition: From the start of the year to August, due to work and other reasons, there was noticeable weight loss, and diet was irregular. No other abnormalities.
Medical history: None
First follow-up question: Hmm, let me wait and see. As mentioned above, do I need to take medication? I'm absolutely certain I won't have an abortion. I haven't

Doctor's answer:

Hello: There are many reasons for menstrual disorders, including inflammation, tumors, and post-abortion. They are closely related to mental state, diet, and rest. You can pay attention to the following matters:
1. Maintain a pleasant mood and avoid mental stress and emotional fluctuations. Some individuals may experience lower abdominal distension, back pain, breast tenderness, mild diarrhea, fatigue, drowsiness, emotional instability, irritability, or tendency to depression during menstruation, which are all normal and do not require excessive concern.
2. Pay attention to hygiene to prevent infection. Keep the external genital area clean. Sexual intercourse is absolutely forbidden during menstruation. Pay attention to warmth and avoid cold exposure. Avoid overexertion. Those with heavy menstrual flow should avoid consuming brown sugar.
3. Underwear should be soft, cotton, and have good ventilation and breathability. Wash and change underwear frequently, and dry the washed underwear in the sun.
4. Avoid eating cold, sour, spicy, or other stimulating foods. Drink plenty of warm water to maintain regular bowel movements. Those with blood heat should consume more fresh fruits and vegetables before menstruation and avoid stimulating foods like garlic, scallions, chives, and ginger. Those with qi and blood deficiency should increase their nutritional intake, such as milk, eggs, soy milk, pork liver, spinach, pork, chicken, and mutton, while avoiding cold fruits and vegetables.