Irregular Periods

We hear a lot about the menstrual "cycle," which can make it sound as though it happens like clockwork. And we say that a woman who gets her period every 4 weeks is "regular," as though there's usually something abnormal about women who don't. In fact, most women don't get their periods at exactly the same number of days after the last one.

Let's take a look at what happens when a girl gets her first period (also known as menarche , pronounced men -nar-kee). For most girls, this happens between the ages of 9 and 16.

Your menstrual cycle occurs in stages, which doctors often talk about in terms of 28 days. But 28 is just an average figure that doctors use. Women's cycle lengths vary - some have a 24-day cycle, some have a 34-day cycle. The only thing you can usually count on is that if you're not pregnant, nursing, or ill, you will get your period again.

The first day your period comes is Day 1 of your cycle. Around Day 5, your pituitary gland tells your ovaries to start preparing one of the eggs they contain for release. One egg will mature completely, and at the same time the lining of your uterus gets thicker. The lining becomes thick to prepare a nesting place for the fertilized egg in the event that you become pregnant. On or about Day 14, the egg breaks loose (which is called ovulation ) and makes its way through the fallopian tube into the uterus. If the egg hasn't been fertilized by sperm, it will disintegrate. About 2 weeks later, the lining and egg leave your body as your period and the whole thing starts all over again - that's why we use the word cycle .

All this sounds very neat and orderly, but your body may not follow this schedule exactly. It's not unusual, especially in the first 2 years after menarche, to skip periods or to have an irregular menstrual cycle. Illness, rapid weight change, or stress can also make things more unpredictable because the part of the brain that regulates periods is influenced by stuff like this.

Some girls always have irregular periods; others get theirs every 28 days like clockwork. Many are regular most of the time, but occasionally skip a period or get an extra period during times of pressure or stress. In fact, you may notice that when you go on a trip or have a major change in your schedule your period is late.

The length of your periods may also vary - sometimes your period may last 2 days, sometimes 10. That's because the level of hormones your body manufactures can be different from one cycle to the next and this affects the amount and length of bleeding.

So how can you tell when you're about to get your period? If you're not regular, you'll want to pay attention to the clues your body may give you. These include:

• back cramps or stiffness
• heavier breasts or breast soreness (this will happen after ovulation and before you get your period)
• headaches

acne breakouts

• disturbed sleep patterns
• mood swings

If you're not taking birth control pills , you're not pregnant, and you're not having other symptoms such as stomach pain, then it's very likely that your irregular periods are part of the normal changes that can happen when you're a teen. At some point as you grow, your cycle will probably settle into a recognizable pattern.

Some teens may develop irregular periods - or stop having periods altogether - as a result of a hormone imbalance. Disorders of the thyroid gland can cause menstrual irregularities if the levels of thyroid hormone in the blood become too low or too high. Some women have irregular periods because their bodies produce too much androgen. High amounts of androgen can also cause hair growth on the face, chin, chest, and abdomen, and is sometimes associated with excessive weight gain.

If a teen has one of these problems, or if her periods are irregular for other reasons, the doctor may prescribe hormone pills or other medications that will help her to have regular periods.

In the meantime, if your periods are irregular, try keeping some pads or tampons in your backpack, just in case.

It's important to see a doctor if you're sexually active and have missed a period - this could be a sign that you're pregnant. You should also see your doctor if you start having periods that last longer than 7 to 10 days or are accompanied by severe cramping or abdominal pain.