Hypomenorrhea or hypomenorrhoea, also known as short or scanty periods, is extremely light menstrual blood flow. It is the opposite of hypermenorrhea which is more properly called menorrhagia

Menorrhagia

Menorrhagia is an abnormally heavy and prolonged menstrual period at regular intervals. Causes may be due to abnormal blood clotting, disruption of normal hormonal regulation of periods or disorders of the endometrial lining of the uterus...

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Overview

In some women it may be normal to have less bleeding during menstrual periods. Less blood flow may be genetic and, if enquiries are made, it may be found that woman’s mother and/or sister also have decreased blood flow during their periods. Pregnancy can normally occur with this type of decreased flow during the period. The incidence of infertility is the same as in women with a normal blood flow. Constitutional scanty menstruation perhaps best explained by assuming the presence of an unusual arrangement, or relative insensitivity, of the endometrial vascular apparatus.

Reduced menstrual flow is a common side-effect of hormonal contraception

Hormonal contraception

Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...

 methods, such as oral contraceptive

Oral contraceptive

The combined oral contraceptive pill , often referred to as the birth-control pill or colloquially as "the Pill", is a birth control method that includes a combination of an estrogen and a progestin . When taken by mouth every day, these pills inhibit female fertility...

 pills, IUDs that release hormones (such as Mirena), or hormonal implants such as Depo-Provera. The relatively low estrogen contained in most hormonal contraceptives reduces the growth of the endometrium

Endometrium

-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...

, so there is relatively little endometrium left to be shed during menstruation

Menstruation

Menstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...

. Many women find this side-effect to be a benefit of hormonal contraceptive use.

Scanty menses or periods can occur normally at the extremes of the reproductive life that is, just after puberty and just before menopause. This is because ovulation is irregular at this time, and the endomaterial lining fails to develop normally.
But normal problems at other times can also cause scanty blood flow. Anovulation due to a low thyroid hormone level, high prolactin level, high insulin level, high androgen level and problems with other hormone can also cause scanty periods.

Despite these common causes, hypomenorrhea is still technically an abnormality of the menstrual flow, and other underlying medical problems should be ruled out by a doctor.

Disorders causing scanty menstruation

• One cause of hypomenorrhea is Asherman's syndrome
  Asherman's syndrome
  Asherman's syndrome , also called "uterine synechiae" or intrauterine adhesions , presents a condition characterized by the presence of adhesions and/or fibrosis within the uterine cavity due to scars...
  
   (intrauterine adhesions), of which hypomenorrhea (or amenorrhea) may be the only apparent sign. The degree of menstrual deficiency is closely correlated to the extent of the adhesions.

• Uterine: Scanty loss sometimes means that the bleeding surface is smaller than normal, and is occasionally seen when the endometrial cavity has been reduced in size during myomectomy or other plastic operation on the uterus. However, it rarely indicates uterine hypoplasia because the presence of this condition in a uterus which is responsive to hormones indicates ovarian under-activity, and this manifests itself by infrequent rather than scanty menstruation.

• Nervous and emotional: Psychogenic factors like stress due to exams, or excessive excitement about an upcoming event may cause hypomenorrhea. Such factors suppress the activity of those centers in the brain that stimulate ovaries during the ovarian cycle (to secrete hormone like estrogen and progesterone), and may result in low production of these hormones.

• Low body fat: Excessive exercise and crash dieting can cause scanty menstrual periods when the proportion of body fat drops beneath a certain level. It may cause a total absence of periods (also called amenorrhea).

Diagnosis

• Blood Tests: Most of the common cause of decreased flow of blood during the menses can be detected by blood tests. Tests for the level of hormones like FSH, LH, estrogen, prolactin, insulin are important. In polycystic ovarian disease, there will be high levels of insulin and androgens.
• Ultra sonogram: An ultra sonogram can diagnose the thickness of the endometrium, size of the ovaries growth of follicles, ovulation and other abnormalities.
• Other tests: Tests like D & C and MRI scans are some times needed to find out the cause of scanty blood flow during the periods.

Treatment

Unless a significant causal abnormality is found no treatment other than reassurance is necessary. Otherwise, treatment is determined by the diagnosis of any significant causal abnormality.

External links

• Medicinenet Article on Vaginal Bleeding