Causes for Irregular Periods Symptom:
Perimenopause brings changes in your menstrual cycles. For one thing, your periods often become irregular. The most frequent sign of the coming change is shorter periods. During your fertile years you usually have a cycle of about 28 days. But in perimenopause this cycles can vary from 21 to 25 days between cycles and then 60 days to the next cycle. This symptom can be alarming, but once you are used to irregularity, it can be easily controlled.

Heavy bleeding is a different story. It sometimes is transitory; this way having it only for a couple months and then stop. It can also happen as bleeding between periods. This can range from slight spotting to flooding, and it can last for a few days or continue without stopping. Heavy bleeding is annoying and can interfere with your life. Most cases, this symptom is usually associated to hormonal shifts. Sometimes don't, this are the ones that can present a more serious illness.

The type of irregularity your periods may be as follows:

• Shorter periods: (Your period comes more frequent) usually signal that you are producing lower levels of estrogen during your pre-ovulate stage -- and that your FSH levels are higher than normal. With more FSH (Follicle-stimulating hormone) to stimulate them, your follicles are developing faster -- which shortens your cycle.

• Extremely light periods: Usually means that you aren't making enough estrogen to build up your uterine lining. It can also be a sign of an anovulatory period.

• Extremely heavy bleeding: Is also often a sign of an anovulatory period, but in this case, estrogen builds up the uterine lining at the same time that you aren't producing enough progesterone (since you haven't ovulated and so created a corpus luteum). Without progesterone to stop it, the uterine lining keeps building up, until the estrogen production finally drops off and the lining is shed.

• Skipped/less frequent periods: Usually happens as your ovaries continue declining and your menstrual cycle starts cycling down. Over time, even extremely high levels of FSH don't produce enough estrogen for eggs to mature and for your uterine lining to thicken. As you get closer to menopause, your menstrual cycle usually lengthens. Periods come less frequently, there's more time between them. Then you may begin skipping periods. And eventually, in the biggest change in your menstrual cycle, you will stop having periods altogether.

One important point: You should be aware that some irregularities in your menstrual cycle may not be related to premature menopause, but could be a sign of some abnormality. These could be cancer, polyps, non-malignant tumors, or fibroids. If you've had a check-up and there's nothing wrong with you, your irregular periods are probably caused by an hormonal shift.

The most common cause of heavy bleeding and abnormal periods in perimenopausal women is hormonal fluctuations that result from an imbalance of estrogen and progesterone.