What it means

PMS is a group of symptoms that happen in the luteal phase — the week or so before a period — and settle once bleeding starts.

PMDD is a severe, disabling form of it, characterised by significant mood symptoms, and it is a recognised condition with specific treatments.

The mechanism is real: progesterone and oestrogen levels fall in this phase, which affects serotonin signalling among other things. PMS is not a character weakness, not “just being hormonal”, and not imaginary.

What can vary

  • How many people are affected. Estimates vary widely, but a substantial minority experience symptoms, and many more notice mild ones.
  • Symptom type. Common physical symptoms include bloating and water retention, breast tenderness, headache, acne, tiredness and food cravings. Emotional symptoms include irritability, mood swings, sadness, anxiety and difficulty concentrating.
  • Intensity varies enormously, from mild to completely disabling.
  • Timing helps distinguish PMS from something else: symptoms that start a week before and resolve within a few days of bleeding starting.
  • Not everyone gets PMS at all, and people who do not are not doing anything wrong.

Possible explanations

A clinician considers: PMS; PMDD; thyroid problems; anaemia; and mental health conditions that happen to coincide with the cycle rather than being caused by it.

The key question is always whether the symptoms track the cycle. A symptom diary across two or three cycles is genuinely the most useful diagnostic tool here, and apps exist for exactly that.

Warning signs

  • Severe depression, hopelessness, anxiety, or any thought of harming yourself. Get urgent help. There is no reason to sit with that alone.
  • Symptoms that stop you functioning every cycle — this suggests PMDD rather than PMS, and PMDD has specific effective treatments.
  • Symptoms that are getting worse over months rather than following the cycle.

What to do next

Track symptoms for two or three cycles — when they start, how bad, and what helps. This is the single most useful thing you can do before an appointment.

If mood symptoms are severe, say so clearly and use the word “PMDD”. It changes how a clinician approaches the appointment.

Self-care

Evidence-supported options, roughly in order:

  1. Regular exercise — the most consistently helpful intervention for PMS mood symptoms.
  2. Steady sleep and reduced alcohol around the premenstrual week. Alcohol magnifies PMS symptoms for many people.
  3. Calcium-rich foods or a supplement where appropriate — there is some evidence, though results vary.
  4. Anti-inflammatory painkillers for physical pain.
  5. Reducing caffeine if you notice it amplifying symptoms.

What does not work reliably: most herbal remedies sold for PMS, and “detox” products. The evidence is poor and the price is high.

When to seek help

Routine: PMS symptoms you can manage.

Prompt: symptoms that disrupt your life every cycle.

Emergency: suicidal thoughts, or severe hopelessness. Contact a crisis line or your local emergency number. In the UK, Samaritans is on 116 123; elsewhere, find your local service — crisis support lists how to find one.

How to talk about it

“The week before my period I feel really low and it affects my work.”

“I think my mood crashes every cycle. Would you check if it’s PMDD?”

“I get really anxious and tearful in the days before my period.”

Naming the timing — “every month, a week before my period, and it lifts when it starts” — is what makes this diagnosable.

Sources

Public sources are linked so you can read the detail rather than take this site’s word for it. None of this has yet been reviewed by a qualified clinician — see how we handle medical review.

Keep reading

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References

Where this comes from

Linked so you can check it against a recognised public health source rather than take this site's word for it.

  1. Premenstrual syndrome (PMS) — NHS NHS (opens in a new tab)
  2. Periods and PMS — NHS NHS (opens in a new tab)

These are public sources from recognised health organisations, linked so you can read the detail rather than take this site's word for it. Reading them does not tell you whether any of it applies to you, and none of these articles has yet been reviewed by a qualified clinician. How we handle sourcing and review.