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What is Premenstrual Syndrome (PMS)?
Summary
PMS is a collection of physical, psychological, and behavioural symptoms that appear in the luteal phase - the one to two weeks before a period - and typically ease once bleeding starts. With over 150 possible symptoms, each person's pattern is unique. This article explains what PMS is, why hormone sensitivity is thought to drive symptoms, how common it is, and how to get a clinical diagnosis through cycle tracking. It also outlines treatment options across medical, complementary, and lifestyle routes.
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🌿 Key takeaways
What is PMS: what to know
- PMS affects an estimated 75% of people who menstruate, though the true figure may vary - it is one of the most common conditions affecting reproductive-age people
- Symptoms occur in the luteal phase (the one to two weeks before a period) and typically resolve within a few days of bleeding starting
- PMS is not caused by abnormally high hormone levels - it is driven by individual sensitivity to normal hormonal changes, particularly to allopregnanolone
- Diagnosis requires two months of tracked symptoms showing a luteal-phase pattern - tracking is the most important first step
- A wide range of treatments exists - from NSAIDs and SSRIs to CBT, supplements, exercise, and stress management - and finding the right combination is personal
What is PMS?
PMS (premenstrual syndrome) is the collective name for a group of physical, psychological, and behavioural symptoms that occur in the luteal phase of the menstrual cycle - the two weeks between ovulation and a period. There are thought to be over 150 symptoms, ranging from bloating and acne to confusion and mood swings. They disrupt normal functioning at work, school, in relationships, and in daily life, and typically resolve within a few days of a period starting.
What causes PMS?
The exact cause is unknown. If PMS were simply caused by hormones, everyone who menstruates would have it - but hormone levels in people with PMS are the same as in those without. The leading theory is that PMS comes down to individual sensitivity.
Specifically, sensitivity to allopregnanolone - the neurosteroid produced when progesterone is broken down. Allopregnanolone activates GABA receptors in the brain, which regulate emotions such as anxiety, stress, and fear. In high concentrations it is calming; in lower concentrations it triggers negative mood. People with PMS are thought to be more sensitive to these fluctuations, and their GABA receptors may respond differently to allopregnanolone altogether. Genetics, stress, and lifestyle factors are also thought to play a role. Read more about the causes of PMS and PMDD here.
🧠 In simple terms: PMS is not caused by "too many hormones." It is caused by the brain responding unusually strongly to normal hormonal changes - which is why it is increasingly understood as a neurobiological condition, not just a hormonal one.
How many people experience PMS?
Around 75% of naturally cycling people are thought to experience PMS. Because PMS is under-researched and under-funded, and because there is no physical test for it, studies return a wide range of figures - from 32% to 90%. Whatever the precise number, PMS is incredibly common. If you experience it, you are far from alone.
PMS symptoms
With over 150 possible symptoms, no two people's experience of PMS is the same - and the combination of symptoms can vary cycle to cycle too. The following covers the most common, but is not exhaustive. If you notice a physical or emotional change in the weeks before your period that disrupts daily life, it could be a symptom of PMS.
Physical symptoms
Bloating
Many people experience uncomfortable bloating or fluid retention during the luteal phase - feeling full, clothes tightening around the waist, or slight weight gain. Read more on PMS and bloating.
Breast and nipple tenderness
Soreness, tenderness, or swelling in the breasts and nipples in the weeks before a period is a very common PMS symptom.
Headaches
PMS-related headaches may be linked to hormonal fluctuations or changes in blood flow to the brain. Severe cases can become menstrual migraines, accompanied by nausea, vomiting, and sensitivity to light and sound.
Cramps
Cramps can occur before the period as well as during. They happen when the uterus contracts, compressing blood vessels and reducing blood supply. Pain can be felt in the stomach, back, or thighs, and ranges from mild to severe.
Fatigue
Low energy levels in the luteal phase are common and often compounded by disrupted sleep, which many people also experience during this phase.
Spots and acne
Hormonal acne is more likely to flare in the luteal phase due to drops in oestrogen and progesterone triggering increased sebum production. This can affect self-esteem and compound the psychological impact of PMS.
Psychological symptoms
Mood swings
Mood swings can shift quickly - from a great mood to deep low within minutes, or becoming upset by things that would not normally cause distress. Irritability, sadness, anxiety, and hopelessness can all be part of the pattern.
Anxiety
Anxiety is one of the most common PMS symptoms. One study found that up to 70% of people feel anxious in the weeks leading up to their period.
Depression
A drop in serotonin levels during the menstrual cycle can cause persistent low mood or depressive feelings. It is also worth noting that up to 50% of people seeking PMS treatment may already have underlying depression or anxiety. If severe PMS depression is significantly affecting your quality of life, speak to your GP. If you are having suicidal thoughts, please call 999, go to A&E, or contact Samaritans on 116 123.
Behavioural symptoms
Trouble sleeping
Scientists believe that rising progesterone levels increase internal body temperature, which can prevent sleep onset and cause disturbances. Cramps, pain, and stress compound the effect.
Change in libido
Libido typically drops during the luteal phase as oestrogen and testosterone are lower. However, some people find their desire increases - as the pleasure of sex can reduce symptoms like low mood and stress.
⚠️ Symptoms vary: Not everyone experiences all these symptoms, and the severity and duration vary widely. Symptoms can also shift from cycle to cycle and during different life stages - particularly during periods of high stress or after pregnancy.
When does PMS start?
PMS symptoms typically begin one to two weeks before a period - during the luteal phase - and are often at their worst in the days immediately before bleeding starts, then improve or disappear once menstruation begins. PMS can start from puberty onwards, up until menopause. It most commonly becomes noticeable in the early 20s.
PMS diagnosis
PMS is diagnosed by a GP after you show evidence of symptoms occurring one to two weeks before your period, consistently for at least two months, affecting daily life, and subsiding once the period begins. If you think you have PMS, start noting your symptoms - when they occur and how severe they feel - and bring that record to your GP. For guidance on talking to a GP about PMS, read our article here.
If your symptoms are severe enough to significantly affect your quality of life, you may have PMDD. Do not wait to seek medical advice if you are concerned.
🌿 Track with Evelyn: Download The Evelyn Premenstrual Health Tracker - a free, printable daily log designed to take to a GP appointment.
PMS treatment options
A wide range of options can help ease PMS symptoms and allow you to go about daily life. Always speak with a qualified healthcare provider to find what works best for you.
Medical treatments
- Over-the-counter pain relief: paracetamol and NSAIDs (ibuprofen, naproxen) relieve cramps, headaches, breast pain, and other physical PMS symptoms without a prescription
- Combined oral contraceptive pill: pills containing drospirenone have been shown to improve severe PMS symptoms when taken continuously - speak to your GP about this approach
- Oestrogen patches or gel: can improve both physical and psychological PMS symptoms
- SSRIs and SNRIs: effective for reducing PMS symptoms, sometimes providing relief in as little as three days; can be taken continuously or only in the luteal phase
- Diuretics: spironolactone and similar water pills can help with physical symptoms including bloating
- CBT: cognitive behavioural therapy is a recognised treatment option for psychological and psychosomatic PMS symptoms
- GnRH analogues: suppress ovarian hormone production; recommended only for severe PMS when other options have not worked
- Surgery: the only permanent cure for PMS; involves removal of the ovaries (and sometimes the uterus, fallopian tubes, and cervix); induces surgical menopause; only considered as a last resort when all other treatments have failed
Alternative and complementary therapies
Acupuncture, aromatherapy, chiropractic, reflexology, and traditional Chinese medicine have all been shown to reduce symptoms including stress, anxiety, bloating, and low mood. Read more on complementary therapies for PMS.
Supplements including calcium, vitamin D, magnesium, vitamin B6, chasteberry, ginkgo biloba, and evening primrose oil can help ease symptoms for some people. Always seek medical advice before starting supplements, especially if pregnant, breastfeeding, or on other medication. Read more on PMS and supplements.
Lifestyle changes
One of the first things your GP may suggest is making changes to your daily routine. Try making one change at a time rather than overhauling everything at once.
- Exercise: trials show that all types of exercise - cardio, yoga, pilates - can significantly reduce PMS symptom severity
- Diet: including calcium-, iron-, zinc-, and vitamin D-rich foods can help ease symptoms. Consult a healthcare professional before adding supplements. Read more on PMS and nutrition.
- Stress management: yoga, meditation, and breathwork, alongside time in nature, have all been shown to have a calming effect on the mind. Reducing stress before and during the luteal phase can ease symptoms in both the current and next cycle
Related articles
- Can supplements really help PMDD? Here's what the science says
- Evelyn's guide to talking to your GP about PMS and PMDD
Disclaimer: This content is for informational purposes only and is not intended as medical advice. Always speak to a qualified healthcare professional about any health concerns.
