Premenstrual syndrome (PMS) refers to a cyclic disorder characterized by emotional, behavioral, and physical symptoms during the luteal phase of the menstrual cycle, which resolve spontaneously after the onset of menstruation. The symptoms of PMS can significantly affect daily work and life. Severe emotional instability is referred to as premenstrual dysphoric disorder (PMDD).
Etiology
The exact cause remains unclear, but it is thought to involve psychosocial factors, ovarian hormone dysregulation, and neurotransmitter abnormalities.
Psychosocial Factors
A high placebo response rate of 30%–50% has been observed in patients with PMS, and some patients exhibit prominent psychological symptoms. Emotional stress often exacerbates existing symptoms, suggesting an interaction between the social environment and psychological factors in the development of PMS.
Ovarian Hormone Dysregulation
Initial theories proposed that an imbalance in the ratio of estrogen to progesterone contributed to PMS, with insufficient progesterone or reduced progesterone sensitivity in tissues leading to relatively high estrogen levels. This was believed to cause sodium and water retention, resulting in weight gain. However, recent studies have found no absolute or relative progesterone deficiency in PMS patients, and supplementation with progesterone has proven ineffective in relieving symptoms. It is now thought that the withdrawal of estrogen and progesterone during the late luteal phase may play a role. Clinical studies have shown that supplementation with combined estrogen-progesterone preparations to stabilize hormonal fluctuations effectively alleviates symptoms.
Neurotransmitter Abnormalities
Patients with PMS exhibit abnormally low levels of endogenous opioids (such as beta-endorphins) during the late luteal phase, leading to withdrawal-like symptoms that affect emotional, psychological, and behavioral states. Additionally, changes in serotonin and other neurotransmitter activity have also been implicated.
Clinical Presentation
PMS is most prevalent among women aged 25–45 and is characterized by cyclic, recurrent episodes. Symptoms typically begin 1–2 weeks before menstruation and rapidly subside or disappear with the onset of menstruation. Major symptoms include the following:
- Physical Symptoms: Headache, back pain, breast tenderness, abdominal bloating, constipation, limb edema, weight gain, and impaired motor coordination.
- Emotional Symptoms: Irritability, anxiety, depression, mood instability, fatigue, and changes in appetite, sleep patterns, and libido. Irritability is the most prominent symptom.
- Behavioral Changes: Difficulty concentrating, reduced work efficiency, memory impairment, nervousness, and excitability.
Diagnosis and Differential Diagnosis
Diagnosis is straightforward based on the characteristic cyclic symptoms occurring during the luteal phase. Diagnosis generally considers the following factors:
- Symptoms consistent with PMS.
- Recurrent occurrence during the luteal phase for at least two consecutive cycles.
- Negative impact on daily work, learning, or social activities.
PMS must be differentiated from mild psychiatric disorders and edema caused by cardiac, hepatic, or renal disease. Basal body temperature records may be useful to assess the relationship between symptoms and ovarian function when necessary.
Treatment
Psychological Therapy
Psychological counseling and support help patients adjust their mental state. Emotional relaxation alleviates symptoms. Cognitive-behavioral therapy may be helpful for those with severe symptoms.
Lifestyle Adjustments
Reasonable dietary and nutritional practices, smoking cessation, and limiting sodium and caffeine intake may be beneficial. Physical exercise can help relieve nervous tension and anxiety.
Pharmacological Treatment
Vitamin B6
Vitamin B6 may regulate the autonomic nervous system and the hypothalamic-pituitary-ovarian axis, as well as inhibit prolactin synthesis. A typical dosage is 10–20 mg taken orally three times per day, which may improve symptoms.
Anxiolytics
These are suitable for patients with pronounced anxiety symptoms. Alprazolam is commonly prescribed during the premenstrual phase at an initial dose of 0.4 mg orally two to three times per day, with gradual dose escalation up to a maximum of 4 mg/day, continuing until the second or third day of menstruation.
Antidepressants
For patients with significant depressive symptoms, fluoxetine—a selective serotonin reuptake inhibitor (SSRI)—may be effective. A dose of 20 mg is typically administered orally once daily during the luteal phase, significantly relieving emotional and behavioral symptoms but with limited efficacy for physical symptoms.
Aldosterone Antagonists
Spironolactone (20–40 mg orally, two to three times per day) antagonizes aldosterone, promoting diuresis and alleviating fluid retention, as well as improving emotional symptoms.
Oral Contraceptives
By inhibiting ovulation and hormonal fluctuations, oral contraceptives alleviate symptoms and reduce water and sodium retention. Gonadotropin-releasing hormone agonists (GnRH-a) may also be used to suppress ovulation, inducing temporary amenorrhea for four to six cycles when needed.