Her period is still a week away, but the weather in the house is already turning. Yesterday everything was fine; today she is tired of everything, including you. If everything you know about PMS comes from internet jokes, here is the actual explanation. No punchlines, no biochemistry textbook.

What happens in the body

The cycle splits roughly in half. The first half is the follicular phase: estrogen climbs, energy and mood are usually up. After ovulation comes the luteal phase: the body prepares for a possible pregnancy and ramps up progesterone. If there is no pregnancy, then 5–7 days before the period both hormones — progesterone and estrogen — drop sharply.

That drop pulls serotonin down with it — the neurotransmitter that keeps mood level. Less serotonin means a thinner filter between a stimulus and a reaction. Sleep gets worse too, the body retains water, everything feels heavy and drained. So PMS is not “moodiness” or a personality glitch. It is measurable chemistry — roughly the same molecules antidepressants work on.

One thing worth getting straight: this is not a malfunction. It is a normal part of the cycle. For some women it passes almost unnoticed; for others it genuinely knocks them down. And for the same woman, different months can be different.

What it looks like from the outside

The mix is individual, but you will most likely see some of this:

  • Mood. Irritability, sharp swings, tears over small things, anxiety with no visible trigger.
  • Fatigue. She is genuinely worn out even though the day was ordinary. Worse sleep, less energy, everything takes effort.
  • Sensitivity. What was a joke a week ago is an insult today. Any criticism, even mild, lands with double weight.
  • The physical side. Sore breasts, cramping low in the belly, cravings for sweet or salty, bloating, headaches.

The key part: she feels all of this too, and usually knows she is reacting more sharply than normal. Knowing it does not make it easier. Imagine you have not slept for three nights and are still required to be pleasant and productive. That is roughly the deal.

The main mistakes

Saying “is this PMS?” Mistake number one by a wide margin. Even if it is. Especially if it is. In one sentence you dismiss her emotion and appoint yourself her diagnostician. You lose on both counts.

Joking about hormones. PMS jokes are only funny in a room she is not in. At home they are expensive and remembered for a long time.

Proving she is wrong. Logic is not the tool right now. You can win the argument and lose the evening — plus the next couple of days as a bonus.

Getting offended back. Her sharpness is background noise from the phase; your answering grudge is a full conflict with long-term storage. An asymmetric trade, and not in your favor.

Disappearing. Silently going off to “wait it out” for three days reads as “he does not care.” Distance helps, but short distance with a warm background — not an evacuation.

What actually helps

  • Know the context. Open the app, check the cycle day. If it is the last days before the period, at least you understand what is going on and stop taking everything personally.
  • Lower the demands. Do not schedule relationship talks, meeting your friends, or a deep clean for these days. All of it can wait a week.
  • Take over the chores without announcements. Dinner, dishes, kids, groceries — quietly. Not “I helped, please notice,” just done.
  • Food, warmth, quiet. Basic, but it works: something tasty, a blanket, a calm evening with no agenda.
  • One supportive line. “I can see it is a rough day. I am here.” No questions, no “let’s talk about it.” Say it and step back.
  • Do not stockpile. If something genuinely important surfaces on these days, do not swallow it. Come back to it in a week, on neutral ground. A real problem will still be there; a phase problem will dissolve on its own.

When it is not just PMS

There is a line. If 10–14 days of every month turn into hell — panic, depressive crashes, “I cannot keep living like this” — that may be PMDD, premenstrual dysphoric disorder. It is treatable, but by a doctor, not by endurance. Same with pain: if she is regularly flattened and eating painkillers by the handful, that is a reason to see a gynecologist, not the norm.

Your role here is simple: do not diagnose, gently back the idea of seeing a specialist. “You feel this bad every month — let’s find you a good doctor” sounds like care, not like a complaint.

The short version

PMS is chemistry, not character. A few days a month her nervous system runs on different settings, and your job is not to fix it but to stop rocking the boat. The playbook for these days: fewer questions, more things done quietly, one warm sentence, zero hormone jokes. In a few days the cycle will turn the page on its own — but how you behaved this week, she will remember for a long time. In both directions.