Phases of the Menstrual Cycle
The menstrual cycle is divided into four main phases:1. Menstrual Phase
This phase marks the beginning of the cycle and lasts 3-7 days. During this time, the
endometrium (lining of the uterus) sheds, resulting in menstrual bleeding.
2. Follicular Phase
Starting from the first day of menstruation and lasting until ovulation, this phase involves the growth of
follicles in the ovaries. The pituitary gland secretes
FSH, which stimulates follicle development. One follicle becomes dominant and prepares to release an egg.
3. Ovulation
Ovulation occurs around the midpoint of the cycle (day 14 in a 28-day cycle). A surge in
LH causes the mature follicle to release an egg into the fallopian tube. This is the most fertile phase of the cycle.
4. Luteal Phase
Following ovulation, the ruptured follicle transforms into the
corpus luteum, which secretes
progesterone to maintain the endometrium for a potential pregnancy. If fertilization does not occur, the corpus luteum degenerates, leading to a drop in progesterone and the onset of menstruation.
Common Menstrual Disorders
Several conditions can affect the menstrual cycle:Dysmenorrhea
Refers to painful menstruation. Primary dysmenorrhea is common and typically starts soon after menarche. Secondary dysmenorrhea is due to underlying conditions such as
endometriosis or
fibroids.
Amenorrhea
The absence of menstruation. Primary amenorrhea occurs when a girl has not started menstruating by age 16. Secondary amenorrhea refers to the absence of periods for three or more months in women who previously had regular cycles. Causes include
PCOS, thyroid disorders, and extreme weight loss.
Menorrhagia
Heavy or prolonged menstrual bleeding. It can be caused by hormonal imbalances, fibroids, or bleeding disorders.
Oligomenorrhea
Infrequent menstruation, often related to hormonal imbalances, PCOS, or excessive exercise.
Role of Hormones
Several hormones regulate the menstrual cycle:Estrogen
Produced primarily by the ovaries, estrogen helps thicken the endometrium during the first half of the cycle.
Progesterone
Secreted by the corpus luteum, progesterone stabilizes the endometrium during the second half of the cycle.
Follicle-Stimulating Hormone (FSH)
Produced by the pituitary gland, FSH stimulates follicle growth in the ovaries.
Luteinizing Hormone (LH)
Also produced by the pituitary gland, LH triggers ovulation and the formation of the corpus luteum.
Managing Menstrual Health
Good menstrual health can be maintained by: Maintaining a balanced diet and healthy weight.
Regular exercise.
Managing stress through relaxation techniques.
Regular gynecological check-ups.
Severe menstrual pain.
Irregular or missed periods.
Heavy or prolonged bleeding.
Symptoms of hormonal imbalances, such as excessive hair growth or acne.
