Tag: fertility and menstrual cycle

Your menstrual cycle is the full sequence of hormonal and physical changes your body runs from the first day of one period to the first day of the next, not just the days you bleed. Your period is simply the part you can see. Getting to know it is one of the most useful things you can do for your health: it helps you make sense of your periods, spot your own patterns, and notice when something’s changed. And yet most of us were taught remarkably little. Hertility’s own peer-reviewed study of 383,085 UK women found that more than one in five didn’t know their cycle length, rising to one in three of those under 25. We really think that needs to change. Here’s exactly what happens between one period and the next: the phases, the hormones behind them, when ovulation happens, and what counts as normal. Quick facts: What is the menstrual cycle? First things first: your period and your menstrual cycle aren’t the same thing. The menstrual cycle is the series of hormonal and physical changes that happen from the first day of one period to the first day of the next.  So, if your period starts on 1 June and your next one starts on 29 June, you had a 28-day menstrual cycle. The first day you have a full bleed is day 1, spotting doesn’t count. Then you count each day until your next period begins. Underneath, two processes run in tandem. The ovarian cycle is what’s happening in your ovaries  – follicles develop, an egg may be released at ovulation, and the ovary then prepares for a possible pregnancy. The uterine cycle is what’s happening to your endometrium (your womb lining) – it sheds during your periodand grows back in preparation for an embryo to implant.  Both are carefully regulated by four cycling hormones – oestrogen, progesterone, luteinising hormone (LH) and follicle-stimulating hormone (FSH) and, as you’ll see, they map neatly onto each other. It sounds complex, but it’s far easier to follow phase by phase. How long is a normal menstrual cycle length? Thinking that every menstrual cycle is 28 days can be misleading for many women. For adults, a cycle of roughly 21-35 days is within the expected range, so 28 days can be perfectly normal, but so can 24, or 31. In fact, a study examining over 600,000 cycles found that only 13% of cycles in the study group were 28-days long – 29.3 days was the average.  Rather than expecting your to body fit a textbook number, it’s far more useful to know what’s usual for you. Further, a little month-to-month variation is common. Illness, stress, changes in exercise, energy intake and weight, and different life stages can all make it a little longer or shorter than expected. A ‘regular’ cycle doesn’t mean your period lands on the same date every month, just that it tends to follow a reasonably predictable pattern. And there’s a real difference between feeling regular and actually knowing your numbers: in Hertility’s research, nearly 5% of women who described their cycles as regular and gave a cycle length were, in fact, reporting one outside the 21-35-day range. Which is exactly why knowing your actual figures beats a vague ‘regular’ or ‘irregular’. What counts as an irregular menstrual cycle? For most adults, cycles that are repeatedly shorter than 21 days or longer than 35 are generally considered irregular, but the numbers aren’t the whole story. If your periods always come every 27-30 days and suddenly start arriving every 40, that change is useful information to know. Plenty of things can influence your cycle, and an irregular period doesn’t automatically mean something’s wrong. Common reasons include the first few years after periods begin (most women’s menstrual cycles don’t regulate until they are ~25 years old) , pregnancy, breastfeeding, perimenopause and hormonal contraception, as well as stress, major changes in weight or energy intake, and intensive exercise. Underlying causes include thyroid conditions, raised prolactin and PMOS, along with some medications. If your periods suddenly become irregular, stay that way for several cycles, or come with other symptoms, it’s worth understanding why. If irregular periods, missing periods or symptoms that don’t quite add up sound familiar, our Online Health Assessment is a good first step towards understanding what’s going on. How long should a period last? A period usually lasts 2-7 days, with 5 to 6 days being most common. Some people naturally have short, light periods; others bleed for longer or more heavily, and flow is often heavier on some days than others. There’s no single pattern everyone has to match, what’s useful is knowing what’s normal for you, so a sudden change stands out. What is a normal amount of bleeding during my period? Rather than chasing an exact millilitre figure, the more useful question is simpler: is your bleeding getting in the way of your life? Signs your periods may be heavy include: Heavy periods can also lead to iron-deficiency anaemia, which may leave you unusually tired, dizzy or short of breath. NICE defines heavy menstrual bleeding by its impact on your quality of life rather than a strict volume, so if it’s disrupting your everyday life, that alone is reason enough to get it checked. You don’t have to just cope. What are the phases of the menstrual cycle? The cycle is usually described in four stages, though they overlap rather than switching cleanly: Biologically, there’s a little overlap between these phases. For example, your period actually happens during the beginning of the follicular phase. But thinking about the cycle in four stages is a useful way to picture what’s happening. The follicular phase: from your period to ovulation The follicular phase starts on the first day of your period and ends when you ovulate. For most people, this phase lasts about 10-22 days, but this can vary. At the start of a new cycle, oestrogen and progesterone are low, so the brain releases gonadotrophin-releasing […]