Menstruation

Definition
noun
The periodic physiologic discharge through the vagina of blood, cervical mucus, vaginal secretions, and endometrial tissue during the reproductive period, and in the absence of pregnancy, as controlled by hormones
Supplement
Menstruation is the recurring discharge of blood, cervical mucus, vaginal secretions, and endometrial tissue of a nonpregnant females of humans and other animals (e.g. certain primates, shrews, and bats.¹ In humans, it usually recurs at about four week intervals, or about a month, thus the Latin derivation of the term from menses, meaning months. Most females report premenstrual symptoms such as bloating, fatigue, breasts tenderness, nausea, and mood changes. Physical and emotional symptoms occurring in about one to two weeks prior to menstruation is referred to as premenstrual syndrome. Other females experience disabling symptoms such as headache, menstrual cramps, and dysmenorrhea.
The first menstruation (called menarche) in a female occurs at the onset of puberty. In humans, menarche usually occurs between the ages of 12 and 15. The first day of menstruation is used for determining the date of the last menstrual period or LMP. The absence of menstruation is referred to as amenorrhoea. It occurs when the female is pregnant (as well as breastfeeding). Menopause is when menstrual period stops permanently. Menstruation is under hormonal control.
Word origin: from menstrual, from Latin mensis ‎(month), menses (plural, months) + -ation
Synonym(s):

• catamenia
• menstrual period
• menstrual bleeding

Compare:

oestrus

See also:

• menstrual cycle
• premenstrual syndrome
• menarche
• menopause
• last menstrual period
• amenorrhoea
• oligomenorrhea
• hypomenorrhea
• polymenorrhea
• hypermenorrhea
• metrorrhagia

Related term(s):

Menstruation-inducing agents

Nonovulational menstruation

Retained menstruation

Reference(s):

¹ Lopez, K. H. (2013). Human Reproductive Biology. Academic Press. p. 53.