What is the difference between PMS and PMDD?

PMS is common premenstrual physical and emotional symptoms. PMDD is a severe, recognised form dominated by intense mood symptoms that seriously disrupt daily life, and it often needs medical treatment.

How do I know it is not depression or anxiety?

In PMS and PMDD the symptoms appear before the period and ease once it starts. Symptoms present all month long point to a different or additional condition — which is why doctors ask you to track symptoms over two or more cycles.

Do supplements like vitamin B6 or magnesium work for PMS?

Some women try them, but the scientific evidence is limited and mixed. Talk to a doctor before relying on them, and do not exceed the recommended doses.

What treatments help severe PMS or PMDD?

The combined contraceptive pill, SSRI antidepressants (first-line for PMDD), and cognitive behavioural therapy, alongside lifestyle measures. A GP or O&G can tailor these to you.

When should I see a doctor about premenstrual symptoms?

When symptoms affect your daily life, work or relationships despite self-help — and urgently if you ever have thoughts of harming yourself, in which case call 995 or the national mindline 1771.

PMS & PMDD: Premenstrual Syndrome Explained (Singapore)

Written & reviewed by the BestDoctors.sg editorial team · Last updated 22 Aug 2026 · General information, not medical advice

Quick answer. Premenstrual syndrome (PMS) is the cluster of physical and emotional symptoms many women get in the 1–2 weeks before a period, easing once the period starts – bloating, breast tenderness, tiredness, food cravings, mood swings, irritability and low mood. Premenstrual dysphoric disorder (PMDD) is a recognised, severe form dominated by marked mood symptoms (depression, anxiety, anger, irritability) intense enough to disrupt work, relationships and daily life. Most PMS is managed with lifestyle measures; significant PMS or PMDD may need treatment such as the combined pill or an SSRI antidepressant. If symptoms are affecting your daily life – and urgently if you have thoughts of self-harm – see a doctor.

Premenstrual symptoms are extremely common, and mild ones are a normal part of the cycle. The key is recognising when they cross into something that’s disrupting your life and is worth treating.

What PMS is

PMS is a combination of physical and emotional symptoms in the days before a period: mood swings, feeling irritable, anxious or low; tiredness or trouble sleeping; bloating or cramping; breast tenderness; headaches; skin or appetite changes; and food cravings. The defining feature is the timing – symptoms build in the week or two before the period and ease once it starts. The cause is linked to the natural hormonal changes across the cycle.

What PMDD is

PMDD is a severe form in which the mood symptoms – marked depression, anxiety, anger and emotional tension – are much more intense and have a much greater impact on everyday life, and can include suicidal feelings. It is a recognised clinical condition, not simply “bad PMS,” and affects a small percentage of women (studies give a range of roughly 3–8%). Diagnosis relies on tracking symptoms across cycles to confirm the premenstrual timing.

Self-help for most PMS

For most people, lifestyle measures help: regular exercise, good sleep, a balanced diet with regular meals, reducing salt, caffeine and alcohol, not smoking, stress management, and keeping a symptom diary for at least two cycles. Simple painkillers can ease physical symptoms.

Treatment for significant PMS or PMDD

When lifestyle measures aren’t enough, a GP or O&G may offer hormonal treatment (typically the combined pill), SSRI-type antidepressants (first-line for PMDD, taken continuously or only in the premenstrual phase), and cognitive behavioural therapy. Supplements such as vitamin B6, magnesium or calcium are sometimes tried, but the evidence is limited and mixed – discuss them with a doctor rather than relying on them, and don’t exceed recommended doses.

Telling it apart from other mood conditions

The defining clue is timing: PMS and PMDD symptoms are confined to the phase before the period and lift after it starts. Conditions such as depression, anxiety or bipolar disorder persist throughout the cycle (though they can worsen premenstrually). This is why tracking symptoms over at least two cycles is central to diagnosis. See a doctor if symptoms are affecting your life, and seek help urgently for any thoughts of self-harm – in Singapore, call 995 in an emergency, or the national mindline 1771 or Samaritans of Singapore on 1767.

Related sexual & reproductive health guides

Related condition guides

Sources

NHS — premenstrual syndrome (symptom list; self-help; treatments including the pill, CBT and antidepressants; when to see a GP; PMDD severity).
American College of Obstetricians and Gynecologists (ACOG) / American Family Physician — PMDD as a recognised condition; prevalence range; diagnostic criteria; SSRIs first-line.
Mayo Clinic — PMS lifestyle and dietary measures (salt, caffeine, regular meals).
SingHealth (HealthXchange) — managing PMS symptoms (Singapore patient education).

General information only. This guide is general sexual and reproductive health information for Singapore, not personalised medical advice or a diagnosis. Sexual health concerns are common and treatable, and a doctor’s consultation is confidential — see a GP, an O&G specialist, or a sexual health clinic such as the DSC Clinic, and anonymous HIV testing is available. In a medical emergency, call 995.