Menstruation & cycle – understanding the body's rhythm

Menstruation is a natural part of the body's biological rhythm, but for many it can be associated with questions, discomfort and uncertainty. The cycle affects not only bleeding, but also hormones, energy, mood and well-being throughout the month. Understanding menstruation and the menstrual cycle can therefore provide greater insight into the body's signals and needs.

This guide provides an overview of how menstruation works, what is normal, and when it may be relevant to respond to changes.

What is menstruation?

Menstruation is the bleeding that occurs when the body expels the built-up uterine lining because pregnancy has not occurred. The bleeding marks the start of a new menstrual cycle and is a sign that the body's hormonal interactions are working.

A period typically lasts between three and seven days, but both the length and amount of bleeding can vary from person to person and from cycle to cycle.

Menstrual cycle – more than just bleeding

The menstrual cycle covers the entire period from the first day of one period to the first day of the next. An average cycle lasts about 28 days, but anything from about 21 to 35 days can be perfectly normal.

The cycle is controlled by hormones that affect ovulation, the lining of the uterus, and the general state of the body. Many people experience changes in energy, appetite, and mood throughout the cycle, even if their period only lasts a few days.

Irregular menstruation

Irregular menstruation means that the cycle varies in length or that menstruation comes unpredictably. This can manifest as skipped cycles, missed periods, or very short intervals between bleeding.

Irregular periods can have many causes, including stress, weight changes, hormonal fluctuations, illness, or life stage. For some, it is a temporary phenomenon, while for others it can be a persistent pattern.

If menstruation changes significantly or disappears over a longer period of time, it may be relevant to seek medical advice.

Heavy menstruation

Heavy periods are experienced when the bleeding is so heavy that it interferes with everyday life. You may need to change pads or tampons very frequently, or the bleeding may last longer than normal.

Heavy periods can be hormonally related, but can also have other causes. Regardless of the cause, it is important to take the symptoms seriously, especially if they are accompanied by fatigue or dizziness, as heavy bleeding can lead to iron deficiency.

Menstrual pain

Menstrual cramps are very common and are caused by the contractions of the uterus as it sheds its lining. The pain can range from mild throbbing sensations to severe pain that radiates into the lower back and legs.

Some people find that menstrual cramps affect sleep, work and daily activities. The intensity of the pain can change over time and through different stages of life.

In case of very severe or disabling pain, it may be relevant to talk to a doctor about possible causes and treatment options.

The body's signals change over time

Menstruation and the menstrual cycle are not static. The body changes throughout life, and so does the cycle. What feels normal during one period may change later.

Noticing changes in bleeding, pain, and cycle length can provide important information about the body's well-being and hormonal balance.

Listening to the body

Menstruation isn't just something that happens once a month. It's part of a larger hormonal interplay that affects both body and mind. Understanding your cycle can be a step towards greater body awareness and self-care.

There is no one right way to have your period. Variation is normal, and your body deserves both patience and attention.

Knowledge base: Sundhed.dk, NHS, Mayo Clinic, American College of Obstetricians and Gynecologists (ACOG)