Irregular menstruation, various causes are discussed... I examined each one carefully.

Irregular menstruation refers to irregularity in the cycle, duration, and amount of menstruation. Professor Bae Na-young of the Department of Obstetrics and Gynecology at Korea University Guro Hospital said, "(In general, irregular menstruation) also includes symptoms such as dysmenorrhea and premenstrual syndrome, which are considered abnormal and are collectively called 'menstrual disorders'." Normal menstruation lasts 3 to 7 days and occurs in a cycle of 21 to 35 days. Although there are individual differences, a menstrual volume of 20 to 60 mL is considered normal. A cycle shorter than 21 days is called frequent menstruation, while a cycle longer than 35 days is called oligomenorrhea. If the menstrual volume is low, it is called hypomenorrhea; if the volume is high or the duration is prolonged, it is called menorrhagia. If menstruation does not occur for more than three months, it is considered amenorrhea.

Polycystic Ovary Syndrome

If women of reproductive age experience irregular menstrual cycles or abnormal menstruation, polycystic ovary syndrome (PCOS) should be suspected first. When PCOS occurs, male hormones increase in the ovaries, making ovulation difficult. Since ovulation itself is not smooth, the menstrual cycle also becomes irregular. An excess of male hormones (androgens) is also called hyperandrogenemia, which can lead to hirsutism, or increased body hair. If both irregular menstruation and hirsutism are present, it is highly likely to be PCOS. Polycystic ovary syndrome can be treated with hormonal therapy.

Thyroid disease=

Thyroid hormones can also affect menstruation. When thyroid hormone levels decrease, the pituitary gland secretes more thyroid-stimulating hormone. At this time, hyperprolactinemia, which involves high levels of prolactin (the hormone responsible for milk secretion), can also occur. This suppresses gonadotropin hormones, leading to a lack of stimulation of the gonads such as the ovaries, and consequently, a decrease in sex hormones. The insufficient secretion of sex hormones results in irregular menstruation. Sudden weight changes, abnormal blood pressure, and other symptoms observed alongside menstrual irregularities may indicate a thyroid disorder, and it is advisable to undergo testing. Thyroid disorders occur because there is either an excess or deficiency of thyroid hormones, so treatment aims to restore hormonal balance.

Brain tumor=

There are cases where tumors develop in the pituitary gland, causing menstrual irregularities. When a tumor in the pituitary gland grows, it can destroy normal pituitary tissue and lead to excessive secretion of prolactin. Excessive prolactin secretion can result in decreased menstrual flow or persistent amenorrhea. In particular, if a tumor develops in the cells that secrete prolactin, it can lead to decreased libido and symptoms of milk production, so if these symptoms appear along with menstrual irregularities, a brain tumor should be suspected. Brain tumors are treated with hormone therapy to restore pituitary function and surgery to remove the tumor.

Underweight=

Underweight can cause hormonal imbalance, which may lead to irregular menstruation. Professor Bae Na-young explained, "There are hormones secreted from the ovaries and hormones produced from body fat in women," and added, "If someone is underweight, they have less body fat, so female hormones are also relatively less secreted." However, irregular menstruation is more likely to occur when experiencing rapid weight loss rather than being naturally underweight. Professor Bae stated, "Excessive dieting and other factors can affect body fat, leading to hormonal imbalance and resulting in irregular menstruation." In such cases, returning to a normal weight typically causes the irregular menstruation to resolve naturally.

▷Excessively thin endometrium=

The endometrium is thin, which can lead to abnormal uterine bleeding and menstrual irregularities. The endometrium proliferates and sheds under the influence of female hormones, causing its thickness to continually change. Professor Bae Na-young stated, "The secretion of female hormones should fluctuate periodically, increasing and decreasing, but if it changes rapidly, the endometrium may not thicken properly, leading to increased bleeding." The thickness of the endometrium can be checked through ultrasound examination, but clinical research on treatment methods is still ongoing.

Ignoring amenorrhea can increase the risk of endometrial cancer, so caution is needed. Professor Bae Na-young said, "Some people think it's convenient not to have periods, but it actually puts a burden on the uterus," and "if amenorrhea persists, the influence of female hormones continues on the endometrium." She continued, "Since the endometrium is continuously exposed to female hormones, it keeps proliferating, which can lead to endometrial hyperplasia," and this can, in severe cases, progress to endometrial cancer.

Conversely, if experiencing heavy menstrual bleeding, there is a high risk of suffering from chronic anemia. Especially, if the body adapts to this state, symptoms of anemia such as dizziness may not be felt. However, since the heart must supply oxygen at normal levels, the burden increases, raising the risk of developing cardiovascular diseases.