A menstrual cycle is the body's recurring process where hormones control the maturation of an egg, the preparation of the uterine lining, and menstrual bleeding if pregnancy does not occur. Knowing your cycle can make it easier to understand your body's signals, plan contraception or pregnancy wishes, and assess what feels normal for you.
The cycle is typically counted from day 1 of bleeding until the day before the next bleeding starts. Many experience variations from month to month, and it is common for the cycle to change throughout life.
Menstrual cycle length and what is normal
When asking "what is a menstrual cycle," it often also refers to its length. According to patient-oriented health information, a normal cycle is often described as approximately 23-35 days, but there can be individual differences.
How to track your cycle in practice
- Day 1: First day of actual bleeding (not just spotting).
- Last day of the cycle: The day before your next menstruation starts.
- Also note the duration and amount of bleeding, as changes over time can be relevant information for you and your doctor.
Menstrual cycle phases: how it happens month by month
The cycle is often described in four phases. This can help you connect symptoms (e.g., breast tenderness or mood swings) to where you are in the process.
The four phases in brief
- Menstrual phase: The uterine lining is shed, and you bleed.
- Follicular phase: The body matures an egg, and the lining gradually rebuilds.
- Ovulation: The mature egg is released from the ovary.
- Luteal phase: The body prepares for a possible pregnancy; if it doesn't occur, hormone levels drop, and a new bleeding starts.
Ovulation: when does it happen, and how can you feel it?
Ovulation often occurs around the middle of the cycle, but the timing can vary, especially if your cycle length varies. Some feel nothing, while others may experience, for example, mild abdominal pain on one side or changes in discharge.
Practical signs you can look out for
- Discharge may become clearer and more elastic around ovulation.
- Some experience increased libido or slight tenderness in the lower abdomen.
- For fertility planning, ovulation tests can be helpful, but they must be used correctly and understood as guidance.
Hormones in the cycle: what controls bleeding, mood, and symptoms?
The interplay of hormones is a central part of the answer to "what is a menstrual cycle." Overall, estrogen and progesterone play an important role in building and maintaining the uterine lining. When hormone levels drop, menstruation is triggered.
What can hormone fluctuations mean in everyday life?
Some experience physical or mental changes such as bloating, tender breasts, fatigue, or irritability, especially in the days before menstruation. If symptoms significantly affect your daily life, it may be relevant to talk to a healthcare professional.
Irregular menstrual cycle: causes, tracking, and when to seek help
A cycle can become irregular for many reasons, such as stress, significant weight changes, high training volume, illness, or hormonal contraception. The most important thing is to find your "normal pattern" and react to clear changes.
A simple checklist for cycle tracking
- Write down the start date of bleeding each month.
- Note pain (0-10), amount of bleeding, and any spotting.
- Mark symptoms such as headache, mood changes, and breast tenderness.
- Consider taking notes in an app or calendar for 2-3 months.
Contact a doctor if you experience, for example
- Very heavy bleeding or bleeding that changes significantly.
- Severe pain that cannot be managed with usual measures.
- Very long or very short cycles over several months.
- Unexpected bleeding between menstruations that continues.
Products that can make sense when the body changes rhythm
If you experience tender or tight breasts around menstruation (or during periods of hormonal changes such as pregnancy and breastfeeding), soft and flexible support can make everyday life more comfortable. One option is a seamless pregnancy and nursing bra, designed to adapt to the body's changes, e.g., Seamless Original Maternity Nursing Bra. For some, an extra adjustment space can also help, e.g., 4 x Bra Extenders.