PMS – all you need to know

PMS stands for premenstrual syndrome and is defined as recurrent physical and psychological symptoms that occur during the luteal phase of the menstrual cycle – that is, the period between ovulation and menstruation, typically 14 to 5 days before menstruation begins.

What characterizes PMS is the pattern: symptoms appear regularly, disappear when menstruation starts, and are completely gone for at least a week afterward. The intensity can vary from cycle to cycle.

The cause of PMS is not fully known, but research points to one important mechanism: some women are particularly sensitive to the fluctuations in hormone levels that occur during the luteal phase – not to the hormone levels themselves, but to the change.

It is particularly the breakdown product of progesterone – called allopregnanolone – that is believed to play a central role. This substance affects GABA receptors in the brain, which regulate mood and emotions. When allopregnanolone levels fluctuate, some brains react more strongly than others.

In addition, sex hormones affect the production of serotonin – the neurotransmitter that regulates mood, sleep, and pain perception. When estrogen and progesterone fall towards the end of the cycle, serotonin levels can drop and cause the typical PMS symptoms.

Over 200 different symptoms have been described in medical literature. The most common are often divided into psychological and physical:

It is important to note that symptoms vary from person to person, and from cycle to cycle. You don't need to have all of them – and you don't need to have them with the same intensity every month for it to be called PMS.

Yes – and the connection is more direct than many realize. When you are stressed, the body increases its production of cortisol. With prolonged stress, the body can use progesterone to produce cortisol. This can further lower progesterone levels – precisely when they are already in freefall towards the end of the cycle. In addition, cortisol's breakdown products can weaken the brain's GABA system, which normally dampens stress responses.".

The result is that persistent stress can significantly amplify PMS symptoms – especially psychological ones, such as irritability, anxiety, and mood swings.

Typical stressors that worsen PMS:

PMDD – premenstrual dysphoric disorder – is a more severe variant of PMS. The mechanisms are the same, but the brain's reaction is stronger. PMDD is defined as a mental disorder and can lead to impaired ability to function in daily life.

There is no cure for PMS, but much can be done to help. Lifestyle changes are the first line of defense – and they have well-documented effects:

• Move your body regularly. Physical activity increases serotonin levels and reduces cortisol production. Even 20–30 minutes of moderate exercise can have a noticeable effect on psychological symptoms. It's good to start in the follicular phase and continue through the luteal phase.
• Track your cycle. When you see the pattern in your symptoms, it's much easier to prepare – and to understand that what you're feeling has a biological explanation and will pass. A cycle app or symptom calendar over two to three cycles can provide valuable insight.
• Adjust your diet in the luteal phase. Reduce salt (counteracts fluid retention), limit caffeine (worsens anxiety and sleep problems), and avoid large amounts of sugar. Instead, eat many small meals to keep blood sugar stable.
• Actively protect your sleep. Sleep deprivation amplifies all PMS symptoms. During the period before menstruation, the body needs extra rest – not more to do.
• Reduce stress in the luteal phase. Try to schedule demanding meetings, difficult conversations, and challenging decisions for other parts of your cycle if possible. This is not about avoiding life – it's about working smartly with your body.
• Talk to your doctor. If symptoms are severe enough to affect work, relationships, or quality of life, treatment options are available. Birth control pills, cognitive therapy, and in some cases, SSRI medications have shown good efficacy for pronounced PMS and PMDD.

Yes. It is more than normal – it is biologically expected for many women. Hormone levels change dramatically during the luteal phase, and these changes directly affect brain activity.

"Many women who have struggled with PMS over time feel unseen and disbelieved, which makes dealing with the symptoms even harder. It is the woman's own experience of severity that determines whether she needs treatment." — Store medisinske leksikon

The fact that you perceive yourself as more irritable, vulnerable, or unrecognizable in the last days of your cycle does not mean there is something wrong with "you." It is hormones in flux – and it will pass again.

Recognizing the pattern, verbalizing it, and helping those around you understand it – that's not using biology as an excuse. It's taking yourself seriously.

Directly on PMS symptoms – no. PMS occurs in the weeks before menstruation and is caused by hormonal fluctuations, not the menstrual product itself.

However, comfort, security, and peace of mind are not insignificant. A menstrual cup that lasts for 12 hours, period underwear or leak-proof underwear that fits securely and doesn't leak – these are factors that remove one burden during an already challenging period.

You should talk to your doctor if one or more of these points apply:

• Symptoms regularly affect your job, studies, or relationships
• You experience intense sadness, anxiety, or anger that is not in line with the situation
• You recognize yourself in the PMDD description above
• Lifestyle measures do not help after two to three cycles
• You experience suicidal thoughts or thoughts of harming yourself

Your doctor will likely want you to keep a symptom calendar for two to three cycles before the consultation. This makes it easier to make the correct diagnosis and find the right treatment.