Having periodically menstrual cycle is expected in women of reproductive age. It is a sign that your body keeps productive in producing an egg for fertilization and pregnancy. And age can play a key role in the change of your menstrual period. Your periods can fluctuate with age, particularly during puberty and years prior to menopause.
In general, change of your periods with age can be classified into 3 major groups; during puberty, adulthood, and perimenopause (the phase of transition between reproductive age and menopause ‘non-reproductive age’).
It is normal for most healthy girls (adolescents) aged 9 to17 years-old to have irregular periods. The reason is due to they are going to the phase of puberty when the fluctuation of hormones are continuously growing to prepare their adulthood.
Typically, the first period in women can be noticed around ages 11 to 15 years-old, but some may get it earlier or later! 
After the first period in their life, it can take about 2 years or even more for the hormonal fluctuation during puberty to get its balance. And it is normal and common for girls to experience some anovulatory cycles in the first few years after they get their first menstruation.
Anovulatory cycle refers to anovulation condition which means there is no egg released. Once the hormone levels become balance and regulated, girls will begin to have regular periods.
The label of ‘regular’ of regular periods doesn’t mean you need to have 28 days of cycle in your menstruation. This can vary from woman to woman. It can be more or less than 28 days – but it comes regularly.
So, to say that your period is regular, you don’t need to have it for every month. But it should come at the same time from month to month or it has about the same length for every cycle.
Medically, adulthood is a term used to describe period when your body stop to grow physically – though there are some parts of the body that continuously grow physically. And for women, adulthood is the time of when they are ready to start a family and their body is ready to have a pregnancy with their partner.
In fact, changes in hormones (particularly such as estrogen and progesterone) can play a key role in disrupting the normal pattern of women’s menstrual periods.
In adulthood, your body has found the balance in hormones. This means that the major factor that can cause irregular periods during puberty has gone, and now the cycles of your menstruation should become regular.
However, not all women in their adulthood are able to always have regular periods. Changes in estrogen and progesterone are not always influenced by the age, because there are also other factors that can cause the imbalance of hormones.
These factors may include lifestyle factors (such as stress or the use of birth control pills ‘particularly when you want to change your birth control pills’) or certain health conditions.
Does irregular menstrual cycle during adulthood need medical intervention?
The answer is closely dependent on the cause of irregular period. If it is caused by lifestyle factors such as too much exercise or high stress, you can improve it with lifestyle approaches and maybe without medical intervention.
Pregnancy and breastfeeding also can have an effect. In fact, late period is one of common signs when you are being pregnant. And after delivery, some moms who breastfeed their baby can experience irregular periods.
But if irregular period is caused by certain health problem, medical intervention is often required. The following are some problems associated with irregular menstrual periods :
- Thyroid disorders, such as both under and over active thyroid.
- Uterine fibroids! It is a kind abnormal growth (benign tumor) that grows on the uterus.
- Asherman syndrome! It is kind of adhesion (severe scarring) that affects the lining of the uterus.
- Polyps that form on the uterine lining.
- PCOS or polycystic ovary disease (it is a kind of hormonal problem that affects women of reproductive age). It can occur when there are cysts (typically very small cysts) that form in the ovaries.
How long does a woman have the cycle of her menstruation? She usually has it until she get her menopause (the phase of non-reproductive age).
So, menopause is actually the time of when you lost your menstrual period permanently. Normally, it usually occurs in the age between 45 and 55 years-old. On average, most women get it in the age of around 50 years-old .
The length of perimenopause (menopause transition) can vary from woman to woman. While some can have it for 2 years, others get it for almost 8 years or even up to 10 years.
Furthermore, there are also a few women who get their perimenopause and menopause earlier than usual. Early menopause usually affects women who have certain health conditions /illness, taking a surgery, or taking other medications.
As you age (particularly after adulthood), your body can experience the declining function in the ovaries! It is the major reason behind perimenopause .
When your ovaries gradually decline in function, there will be numerous changes and symptoms that occur – and one of them is change in your menstrual period!