Menarcheal Dysmenorrhea

　　First, Etiology

　　1. Primary dysmenorrhea

　　The pain is caused by the uterus itself and is not accompanied by pelvic lesions. It is common during ovulatory menstrual periods, so about 75% of those who experience menarche within 6 to 12 months are affected. If ovulation occurs at menarche, dysmenorrhea may start at menarche; 13% of those who start dysmenorrhea in the second year after menarche, 5% in the third year, and only 4% in the fourth year.

　　2. Secondary dysmenorrhea

　　It is rare in adolescent girls and is caused by pelvic diseases such as endometriosis, chronic pelvic inflammatory disease, and pelvic congestion syndrome.

　　Second, Pathogenesis

　　1. The endometrium synthesizes an increased amount of prostaglandin (PG) before menstruation, which leads to an increase in the levels of estrogen and progesterone in the endometrium. This promotes the synthesis of more PG. During the menstrual period, when the endometrium disintegrates, PGE2 and PGF2a are released, causing the uterine smooth muscle to contract strongly, leading to an increase in intracavitary pressure. When the intracavitary pressure exceeds the arterial pressure (>26.7 kPa, i.e., >200 mmHg), the uterus becomes ischemic, resulting in pain symptoms similar to myocardial ischemia. Since PGF2a and PGE2 also act on the smooth muscle of the trachea, intestines, and blood vessels, symptoms such as asthma, nausea, vomiting, diarrhea, and increased blood pressure can occur simultaneously.

　　2. Narrow cervical canal or excessive retroversion of the uterus can obstruct the excretion of menstrual blood, causing increased uterine contractions and dysmenorrhea.

　　3. Uterine hypoplasia often accompanied by abnormal blood supply can cause local ischemia, leading to premenstrual and menstrual abdominal pain.

　　4. When the entire endometrium is discharged, strong uterine contractions can occur, causing abdominal pain, also known as membrane-like dysmenorrhea. The cause of the endometrial non-resolution is unknown, and it is believed that excessive gestagens may be the cause. However, the use of gestagens before menstruation can make some cases of membrane-like dysmenorrhea disappear.

　　5. Other mental traumas, overwork, intense exercise, etc., can worsen dysmenorrhea.

　　In addition to general symptoms, it can also cause other diseases. Severe dysmenorrhea can lead to fainting; asthma and increased blood pressure may occur. Therefore, once detected, it should be treated actively, and preventive measures should also be taken in daily life.

　　1. Primary dysmenorrhea

　　(1) Girls aged 1-3 years (about 14-15 years old) may experience spasmodic pain in the lower central abdomen about 12 hours before menstruation or at the beginning of menstruation. Severe cases may involve the lumbosacral region and abdomen. Symptoms may include nausea, vomiting, diarrhea, or headache, fatigue, etc. Severe cases may have pale complexion, cold extremities, and even fainting. The pain may last for 1-4 days.

　　(2) No symptoms during non-menstrual periods.

　　(3) Normal digital rectal examination and/or pelvic ultrasonography.

　　2. Secondary dysmenorrhea

　　(1) Different from primary dysmenorrhea, abdominal pain occurs after several years of menstruation and is more common in adult women. The characteristics of the pain are that it worsens during menstruation and is also uncomfortable during non-menstrual periods. Non-opioid analgesics are ineffective, and pelvic examination and/or pelvic ultrasonography can detect lesions.

　　(2) Abdominal pain during menstruation and disappearance after menstruation, as well as normal pelvic examination, can be diagnosed as dysmenorrhea, but attention should be paid to secondary dysmenorrhea caused by organic lesions, which sometimes occur simultaneously with primary dysmenorrhea.

　　Regular lifestyle, preventing overwork and mental trauma can alleviate dysmenorrhea, prevent pelvic infection, reduce the number of induced abortions, and can reduce the occurrence of secondary dysmenorrhea. Keeping warm is also something that dysmenorrhea patients need to pay attention to. In daily life, appropriate exercise should be carried out to strengthen their own physique and avoid adverse effects on the body caused by wind and cold.

　　At the time of diagnosis, in addition to relying on its clinical manifestations, it is also necessary to use auxiliary examinations. This disease should undergo abdominal ultrasonography to understand the size of the uterus and whether there are any abnormalities. This disease severely affects the patient's daily life, so it should be actively prevented.

　　Diet should be regular and reasonable, that is, high-protein, high-vitamin foods should be the mainstay, and cold and raw foods should be avoided. The diet of patients should be light and easy to digest, eat more vegetables and fruits, reasonably match the diet, and pay attention to adequate nutrition. In addition, patients should also pay attention to avoid spicy, greasy, and cold foods.

　　I. Treatment

　　1. Primary dysmenorrhea

　　(1) Prostaglandin synthesis inhibitors: start taking the medicine 1 to 3 days before menstruation and continue for 1 to 2 days during menstruation.

　　① Indomethacin (Analgin): 25mg, 3 times a day, about 70% effective; ② Ibuprofen (Isobutylphenylacetic acid): 400mg, 3 times a day, 85% effective; ③ Flubiprofen (Fluorobutylphenylacetic acid): 50mg, every 6 hours, or 100mg, 2 to 3 times a day; ④ Mefenamic acid (Mefenamic acid): 500mg taken at once, then 250mg, every 6 hours; ⑤ Meclofenamic acid (Meclofenamic acid): 100mg taken at once, then 50 to 100mg every 6 hours.

　　(2) Hormonal therapy:

　　① Oral contraceptives: used in the same way as contraception, start taking short-acting oral contraceptives from the 3rd to 5th day of the menstrual cycle, relieve dysmenorrhea by inhibiting ovulation. Due to the decrease in estrogen secretion by the ovary, the synthesis of PG by the endometrium is reduced, and the endometrial hyperplasia is poor, which leads to a decrease in menstrual blood volume and is another reason for relieving dysmenorrhea. Generally, 3 to 6 cycles are taken continuously. Due to the unstable function of the hypothalamus-pituitary-ovary axis in adolescent girls, oral contraceptives may inhibit its function and cause amenorrhea after discontinuation, so it is not the first choice; ② Progesterone: supplementing progesterone 5 to 7 days before menstruation can relieve some dysmenorrhea; ③ Artificial cycle therapy: used for patients with poor uterine development.

　　(3) Antispasmodics: 0.5mg of atropine is injected subcutaneously, which can relax the isthmus of the uterus and alleviate dysmenorrhea.

　　(4) Morphine-like analgesics: due to the risk of addiction, use with caution.

　　(5) Traditional Chinese medicine (Dysmenorrhea Pill, Jiawei Xiaoyao Powder) or treatment with Chinese medicine based on syndrome differentiation.

　　2. Treatment of primary disease for secondary dysmenorrhea

　　II. Prognosis

　　Primary dysmenorrhea usually subsides or disappears after marriage or childbirth, and the prognosis of secondary dysmenorrhea depends on the treatment of the primary disease and its severity.