understanding the menstrual cycle

If you’re here, then I really hope you are aware that women have periods each month, and that these periods are a part of what is called “the menstrual cycle”. But do you know the different stages of the cycle, and the finer details what actually happens?

Understanding these details really helps us connect with our bodies and be armed with the knowledge to track our cycles more closely. Recognising the signs and symptoms that can come with different stages of the cycle can help us feel empowered and enable us to develop better coping strategies.

The menstrual cycle is a natural process that is controlled by hormones that are usually associated with the female body, including oestrogen and progesterone (women have much higher levels of these hormones naturally). It begins in puberty, when teenagers reach sexual maturity and are able to reproduce. During puberty, hormones help prepare the uterus for getting pregnant each month.

Over the course of around 28 days, four different phases take place; the follicular phase, menstruation (period), ovulation and the luteal phase. The organs involved in the menstrual cycle include the ovaries, fallopian tubes, uterus (womb), cervix and vagina.

During this stage, levels of oestrogen and progesterone are at an all-time low. This is the reason why some women are prone to premenstrual syndrome (PMS), which can cause mood swings, tender breasts, food cravings, fatigue and bloating. Low oestrogen and progesterone can also cause trouble sleeping, lack of concentration, headaches and migraines. Fun!

The follicular phase begins on the first day of menstruation, so it overlaps with the bleeding period. This phase lasts for around 13 to 14 days, until ovulation. During this phase, hormones help prepare our uterus and eggs for a possible pregnancy.

Each egg is stored inside a sac, known as a “follicle”. These follicles are found inside our ovaries, and they have been there since we were born! It gets really weird when you consider that your mother was the one who made your eggs when she was making you. Hormones tell the eggs to ripen, and by the end of this phase, the most mature egg will be released during the next phase, called “ovulation”.

Ovulation is the phase when our ovaries release an egg. This happens about 14 days before the start of a period. So, in a 28-day cycle, it would take place on day 14, just after the follicular phase has ended. A rise in two hormones, called oestrogen and luteinising hormone (LH), stimulate our ovaries to release an egg.

Each month, the ovaries alternate in releasing eggs. One month, the left ovary releases an egg, the next month, it’s the right ovary’s turn. After the egg breaks out of its follicle (sac), hairs inside the fallopian tube sweep up the egg and move it into the fallopian tube. It is here that the egg can be fertilised by a sperm, if the time is right! You know, birds and the bees type stuff.

The egg can survive in the fallopian tube for 12 to 24 hours, although sperm can survive up to 5 days once inside a woman’s reproductive tract. This means that if you ovulate on day 15, it’s possible that sperm entering your body on days 10 to 15 could reach your egg and fertilise it. This is worth remembering ladies if you don’t want any surprises.

Around ovulation, oestrogen and luteinising hormone (LH) suddenly drop. This is why some women who are sensitive to oestrogen changes, can experience PMS-like symptoms and those who suffer with migraines are more likely to get them during this time.

The luteal phase begins after ovulation. It involves preparing the body for pregnancy, or for the next period. The empty follicle which released the egg starts producing progesterone. This causes the lining of the uterus to thicken, and mucus to become thicker and stickier. That is why vaginal discharge can also look and feel different during this time.

If a sperm successfully fertilises an egg, the cells begin to develop, and this is referred to as an embryo. The embryo travels down the fallopian tube into the uterus over the course of about 1 week. It will usually implant itself into the wall of the uterus, which is the point you’re officially “pregnant” and can start planning a bigger gender reveal than all your mates had. If the egg has not been fertilised, it will break apart and leave the body along with the menstrual flow.

Oestrogen and progesterone significantly drops towards the end of the luteal phase, which can cause unwanted symptoms in some women, such as PMS. Meanwhile, other chemicals in the body, called “prostaglandins” are produced in the uterus, which cause our muscles to contract and bring on menstrual cramps. In some women, prostaglandin levels are very high, which can cause severe pain and cramping.

Eventually, the blood vessels in the uterus lining rupture, causing the blood to flow out of the body via the vagina. The period has arrived, and the whole menstrual cycle starts again for another month!