If you are experiencing problems with your period, understanding what is happening to your body each month is a good first step to getting your head around what may be happening.
What is your menstrual cycle?
Your menstrual cycle is the monthly series of changes your body goes through to prepare itself for a possible pregnancy. It includes menstruation (i.e. your period), the process by which your uterus (or womb) sheds its lining each month – which you experience as vaginal bleeding. Your cycle also involves ovulation, the process by which an egg is released from your ovaries each month. Ovulation is what enables a potential pregnancy – if the released egg is fertilised by sperm, it can develop into the first stages of a new life, i.e. an embryo. All of these cyclic changes are driven and controlled by hormones, including oestrogen and progesterone.
On average, a girl will first get her period between the ages of 11 and 14. This first period is referred to as menarche and is usually preceded by other signs of puberty, such as breast development and the appearance of pubic hair. Interestingly, in developed countries, menarche is tending to occur earlier in a girl’s life (as young as 8). This is thought to be due to the increased weight that children and adolescents now carry compared to previous generations, but the precise cause is unknown.
A woman’s cycle generally lasts for 28–35 days. However, at the beginning and end of a woman’s fertile years (i.e. menarche and menopause), there may be more variability in the length of the cycle. Additionally, some women will always have cycles of variable length, and will consequently have irregular periods.
What are the phases of the menstrual cycle?
The menstrual cycle is divided into two phases:
If fertilisation has not occurred (i.e. you are not pregnant), you will have your period for 3–7 days. This marks the beginning of the follicular phase.
During this phase, hormones will stimulate your ovaries to produce a number of follicles, each of which contain an egg. Eventually, one follicle will dominate and the development of all other follicles will be suppressed. The dominant follicle will then release its egg in the process of ovulation.
During the follicular phase, the lining of your uterus will also thicken (after your period has finished), in preparation for a possible pregnancy.
After ovulation, the luteal phase begins. The length of this phase is 14 days and its end is marked by the start of your period. Therefore, you can determine when you ovulated by subtracting 14 days from the first day of your period. If your cycle is regular and you’re trying to get pregnant, this can help you determine when you’re most fertile.
Once ovulation has occurred, the follicle from which the egg was released develops into a structure called the corpus luteum. The corpus luteum produces hormones – mainly progesterone, along with small amounts of oestrogen. Progesterone ensures that the thickened lining of the uterus is maintained, in preparation for implantation of a fertilised egg.
If the egg is successfully fertilised after ovulation and implants into the lining of the uterus, the fertilised egg will produce beta hCG – the hormone that is tested for in a pregnancy test. This hormone supports the corpus luteum, which then continues to produce the progesterone required to maintain the lining of the uterus. Maintenance of the uterine lining is important if you’re pregnant.
If fertilisation does not occur, no beta hCG is produced and the corpus luteum will degenerate and die – in which case, the levels of progesterone will drop. This leads to shedding of the uterine lining (menstruation), and the cycle begins again.
What are common problems related to the menstrual cycle?
- Painful periods (dysmenorrhoea): Painful periods are relatively common. If severe, they can interfere with your daily activities. The pain may be attributable to a particular condition (e.g. endometriosis, fibroids), but it may also occur in the absence of any condition. Most commonly, period pain is crampy and occurs in the lower abdomen. Depending on the cause, it may be treatable with simple pain medication (e.g. naproxen, mefenamic acid, ibuprofen) or the combined oral contraceptive pill.
- Abnormal uterine bleeding: Abnormal uterine bleeding refers to periods that are of an abnormal quantity, duration or schedule. Most commonly, it refers to periods that are abnormally heavy or prolonged (also referred to as menorrhagia), but may also refer to abnormal bleeding between periods. There is a wide range of causes for abnormal uterine bleeding and the cause may be determined by investigations such as blood tests, an ultrasound or hysteroscopy. Treatment is often directed at the underlying cause, but it may be as simple as taking the combined oral contraceptive pill. Treatment may also need to address anaemia (low number of red blood cells in your body), which can result from abnormally heavy bleeding.
- No periods (amenorrhoea): There are two forms of amenorrhoea. Primary amenorrhoea is when a girl has not had her first period by the age of 16. Secondary amenorrhoea is when a woman who has previously had her period stops having her period for 3 months (if she has a regular cycle) or 6 months (if she has an irregular cycle). There are many different reasons for the two forms of amenorrhoea, ranging from excessive exercise and stress to conditions such as polycystic ovary syndrome. Treatment is directed at the underlying cause, but in some cases amenorrhoea cannot be treated.
Having problems with your period?
If you have problems with your period that are worrying you or interfering with your daily activities, it’s wise to seek professional advice. As a gynaecologist, I can help treat and manage your symptoms while also investigating for underlying causes. To make an appointment, call (03) 9418 8299 or book online.