Viewing each menstrual irregularity individually and in detail:

Amenorrhea

Yes, even absence of menstruation is a problem.

Amenorrhea is of 2 types, primary and secondary. Primary is when the menstruation never occurs in the first place, and secondary is when it had occurred in the past but then it stops. Gestational amenorrhea is the normal absence of menstruation during pregnancy. Lactational amenorrhea is the absence of menstruation during the period a mother continues to breastfeed her child, which is again, perfectly normal. We will explain the possible causes of primary amenorrhea and secondary excluding gestational and lactational.

Primary amenorrhea

Primary amenorrhea is absence of menstruation. This may be accompanied with presence or absence of secondary sexual characteristics like breast development or body hair.

If your daughter is 14 with normal secondary sexual characteristics, she might just be a late bloomer and you can wait for a year or two. However, if there is no menarche by the time she is 16, you need to see a gynecologist. Similarly, if your daughter does not show any secondary sexual characteristics, then you need to see a gynecologist once she is 14, if there is still no menstruation. The causes are multifactorial, but quite often due to developmental problems.

The causes of the amenorrhea are mainly due to a problem in any one of the following three areas:

1. Hypothalamus
2. Pituitary
3. Ovaries

Together they form a functional endocrine axis, known as the HPO axis.

1. A. Hypothalamic reasons of primary amenorrhea:

As we have explained earlier, a very important hormone called GnRH is secreted by the hypothalamus. This GnrH stimulates gonadotropins in the pituitary gland which then stimulate the release of FSH and LH from ovaries, ultimately causing menstruation and ovulation. A decrease in GnRH release or its absence will never let the menstrual cycle occur.  When the decreased GnrH level is congenital, it is known as Kallman Syndrome.

Functional hypothalamic amenorrhea snubs GnrH levels, directly cutting LH levels and LH surge. The reasons may be over-eating, under-eating, excessive exercising, mental stress, depression, physical stress, etc.

1. B. Pituitary reasons of primary amenorrhea:

When the Pituitary gland fails to release gonadotropins in response to GnRH release by the hypothalamus, the cause clearly lies in this part of the axis. Pituitary tumors are the most common cause. Other examples in which pituitary gland causes are etiological are:

1. Cushing disease
2. hypothalamic tumors
3. Craniopharyngioma
4. Germinoma
5. Brain injury
6. Cranial irradiation
7. Empty sella syndrome
8. Pituitary infarct
9. Hemachromatoses
10. Sarcoidosis

1. C. Then we have another axis for amenorrhea; the ovarian cause:

This is usually due to defective or absent ovarian function. Deformation of gonads is called gonadal dysgenesis. Some causes are:

1. Turner X syndrome
2. Premature ovarian failure
3. Fragile X pre-mutation
4. Swyer Syndrome
5. Polycystic Ovarian disease( more known for secondary amenorrhea)

1. D. There are a few other causes as well that do not fall in either of the categories. They are:
2. Hypothyroidism
3. Hyperthyroidism
4. Sarcoidosis
5. Galactosemia