什么是不规则的时期？

Menstrual cycles don't always run like clockwork. While some women get their periods right on schedule every 28 days, other women are left guessing. Some might skip a month altogether; others might vary from cycle to cycle.

How Many People Have Irregular Periods?

In a South Korean study published inPloS Onein March 2019, over 14 percent of 4,709 adult women ages 19 to 54 reported having irregular menstruation. (1）在另一种情况下，发现职业地位有效：服务，手动过夜轮班和销售人员，而失业的妇女患有不规则的月经周期的风险更高。（（2)

月经时期何时认为不规则？

A normal cycle from the first day of one period to the first day of the next can be anywhere from 21 to 35 days, saysBecky Lynn, MD, the director of the Evora Center for Menopause andSexual Health和an adjunct associate professor of obstetrics and gynecology at Saint Louis University in Missouri: “We all think that 28 days is the normal cycle, but there's actually some room for variability.” To determine whether yourmenstruationschedule is irregular, count from the last day of your previous period and stop counting on the first day of your next. Repeat this for three months. If the number of days between stopping and starting your period is outside of the 21 to 35 days range, you have an irregular cycle. Menstruation can also be considered irregular if your cycle length varies by more than 20 days from month to month. (3)

Why Do Some Menstrual Periods Become Irregular?

There are many variables that can affect the length and timing of your menstrual cycle. Some are correctable, but others can signal significant medical issues.

• Polycystic ovary syndrome (PCOS)这个代谢和hormonal disorder发生卵巢或肾上腺过量产生“雄性”激素（雄激素）并且身体具有insulin resistance。（（4）研究表明，有87％的月经周期女性具有PCOS。（（5)
• Thyroid or pituitary disorders甲状腺功能减退症（（when yourthyroid glanddoesn't produce enoughthyroid hormone),hyperthyroidism（（your gland produces too much), andhyperprolactinemia（（you have too much prolactin, a hormone from your pituitary gland, in your blood) can all affect menstrual regularity, says Dr. Lynn. One study found that 44 percent of study participants with irregular periods also had thyroid problems. (6,7,8)
• Pelvic inflammatory disease (PID)女性生殖系统的炎症，PID通常是由sexually transmitted infections。（（9)

不规则的时期可能是由与非疾病有关的问题引起的

Lynn points out that irregular menstrual cycles can also be caused by:

• PerimenopauseAs you enter the transition to menopause, which can last as long as 10 years, your menstrual cycles will become erratic as part of the process. If you skip more than two periods, you are probably in lateperimenopause。（（10) It’s been estimated that 70 percent of women experience menstrual irregularities in the approach to menopause. (11)
• 压力和anxietyChronic stress or even short-term anxiety about a specific problem can wreak havoc with your hormone balance, causing a missed period and irregular cycle.
• Extreme exerciseExercising too much can throw off the timing of menstrual bleeding and sometimes stop it.
• 饮食失调,极端dieting, or weight lossBeing underweight, whether from extreme exercise, dieting, aneating disorder, or illness, can have the same effect.
• AgeAs mentioned, perimenopause and menopause have a major effect. But being young can create irregularities as well. “Once menstruation begins in young women, it can take several years before it falls into a pattern,” says Lynn.
• 计划生育And not just birth control药片;IUDs, implants, andringscan also cause irregular bleeding.

Irregular Periods May Occur While Breast-Feeding a Newborn

大自然的节育，独家母乳喂养may causeamenorrhea— no menstruation at all — because you are less likely to ovulate for up to about six months. (Learn more before you use this method; many experts recommend new moms pair this approach with an additionalbirth control method, such as condoms, to increase effectiveness.)

Irregular Periods May Occur After Miscarriage, Pregnancy Loss

也称为自发abortion, a流产happens when an embryo or fetus dies before the 20th week of pregnancy. After 20 weeks, pregnancy loss is considered a stillbirth.（（12）“这些事件发生后，可能需要几个月的时间才能再次开始常规时间。”

Should You Be Concerned if Your Period Is Irregular?

每年几个不规则的时期通常不必担心。除此之外，您应该看到医生确保排卵问题或健康状况不是原因。“如果您是一个不使用避孕药的人，而不是年龄或更年期的年龄，并且您的月经不规则，则应提醒您的医生。例如，如果您确实有PCOS，则不规则周期会增加您的风险uterine cancer,” says Lynn.

Can a Missed Period Be Considered Part of an Irregular Period?

Sometimes, a period is late for a very good reason. Before you schedule an appointment with your doctor, you might want to rule out pregnancy.

治疗选择：您可以修复不规则的时期吗？

If stress is a possible culprit in your irregular cycle, try stress management techniques, such as meditation,yoga,太极, visualization, cognitive behavioral therapy, and biofeedback. Avoid over-exercising, and try not to diet excessively. If you need help figuring out what’s best for you, contact a registered dietitian. For all medical issues, consult your healthcare professional.

您可以怀孕不规则的时期吗？

Absolutely yes, says Lynn. “Sometimes you can ovulate with irregular cycles, sometimes you don’t ovulate with irregular cycles. If you're not ovulating, you're not going to怀孕, but if you are ovulating with irregular cycles, you can. You can have bleeding without ovulating but it's a real period only if you ovulate. You should usecontraceptionif not desiring pregnancy and to protect againstSTDs。”

RELATED:Some Period Tracker Apps Are Useful, Help Women Find Fertile Window

没有简单的公式显示那t You Are Ovulating (but You Can Try)

If you are interested in ovulation timing for家庭计划或者any reason, but you have irregular menstrual periods, see your doctor first. If you do have PCOS or another condition, you can get treated as soon as possible.

Can You Calculate Ovulation With an Irregular Period?

Ovulation calculatorsare not very helpful for women with irregular menstrual cycles. Just as you can’t assume you are not ovulating if you have PCOS, you also can’t assume that youare.That’s another reason to get checked out by your doctor soon, so you can begin treatment before your生育能力window closes.

Although none of these生育意识方法（FAM）are foolproof, women with regular or mildly irregular periods may be able to help predict ovulation by monitoring themselves for ovulation symptoms such as changes in cervical粘液或者changes in basal body temperature and by tracking their cycles.

了解有关从信誉良好的资源中解释身体排卵症状的更多信息，例如Taking Charge of Your Fertility或者计划生育。Products such as apps, testing kits, and ovulation monitors may help some women figure out when they are ovulating; talk to your doctor before investing time and money in these products.