PMS and PMDD both cause symptoms before your period, but PMDD is more severe and can have a much greater impact on your daily life. You may experience mood changes, anxiety, tiredness, bloating or breast tenderness with PMS, while PMDD can cause much stronger emotional and behavioural symptoms that affect your work, relationships and normal activities.
Both conditions are thought to involve increased sensitivity to normal hormonal changes across the menstrual cycle rather than simply being caused by abnormal hormone levels. Keeping a daily symptom diary for at least two menstrual cycles can help you and your clinician identify whether symptoms consistently appear before your period and improve once menstruation begins.
What Is Premenstrual Syndrome?
PMS refers to physical, emotional and behavioural symptoms that usually occur during the second half of your menstrual cycle and improve when your period starts. You may experience irritability, bloating, tiredness, breast tenderness or food cravings, with symptoms varying from one cycle to another.
Clinically significant PMS can interfere with your work, relationships, social activities or everyday functioning, although the severity varies considerably between people and cycles. You do not need to experience every possible symptom, and the severity can naturally vary between different cycles.
What Is Premenstrual Dysphoric Disorder?
PMDD is a more severe premenstrual disorder where emotional and behavioural symptoms can become intense. You may experience severe irritability, anxiety, depression, emotional sensitivity or difficulty coping before your period.
Physical symptoms such as bloating, breast tenderness, headaches and tiredness can also occur. The main difference is how strongly PMDD can affect your mood, relationships, work, studies and daily activities, with symptoms usually improving once your period begins.
Is PMDD Just Severe PMS?
PMDD is related to PMS, but it is not simply a casual term for having stronger premenstrual symptoms. PMDD has specific diagnostic criteria and usually involves severe mood or behavioural symptoms that significantly affect your daily functioning.
PMS can also cause symptoms that need treatment, but PMDD tends to have a greater emotional impact. If your symptoms are severe, your clinician may consider both gynaecological and mental health support when planning treatment.
PMS vs PMDD: What Are the Main Differences?
PMS and PMDD can involve many of the same symptoms, so the distinction depends on the overall pattern, severity and effect on your daily life rather than on one symptom alone.
| Feature | PMS | PMDD |
| Timing | Symptoms occur before menstruation and improve after it begins | Follows the same cyclical premenstrual pattern |
| Physical symptoms | Bloating, headaches, breast tenderness, tiredness, appetite changes and sleep problems | Many of the same physical symptoms can occur |
| Emotional symptoms | Irritability, anxiety, tearfulness and mood changes | Severe irritability, anxiety, depression, mood instability or hopelessness may occur |
| Daily-life impact | Can range from mild to significantly disruptive | Causes marked distress or significant interference with work, relationships, studies or daily activities |
| Diagnosis | Based on a repeated clinically significant premenstrual pattern | Usually requires at least five symptoms, including at least one core mood symptom, with clinically significant distress or impairment. The cyclical pattern should generally be confirmed prospectively with daily ratings over at least two symptomatic cycles, although a provisional diagnosis may be made beforehand. |
| Symptom diary | Recommended to establish the cyclical pattern | Prospective daily symptom ratings are important for confirming that the required symptoms follow the premenstrual pattern rather than reflecting an ongoing disorder. |
| Treatment | Lifestyle measures, CBT, hormonal treatment and antidepressants may be considered | May require more structured medical and mental-health treatment |
| Mental-health safety | Mood symptoms can occur | Severe depression and suicidal thoughts can occur and require urgent assessment |
NHS guidance similarly describes PMDD symptoms as much more intense than PMS and potentially having a much greater negative effect on everyday life.
When Do PMS and PMDD Symptoms Occur?
PMS and PMDD usually occur during the luteal phase, after ovulation and before your next period. You may notice symptoms a few days before menstruation or during much of the final one to two weeks of your cycle.
Symptoms should generally begin to improve after menstruation starts, with a substantially improved or symptom-minimal part of the cycle before the next premenstrual phase. If anxiety, depression or tiredness continue throughout the month, another condition may be contributing, even if symptoms become worse before your period.
How Do the Emotional Symptoms Differ?
PMS can cause irritability, mood swings, tearfulness, anxiety or increased emotional sensitivity before your period. The impact can range from mild to significantly disruptive, although PMDD generally involves more severe mood-related symptoms and functional impairment.
With PMDD, emotional symptoms can be much more intense and may include severe irritability, anxiety, low mood, hopelessness or difficulty managing your reactions. Your clinician will consider the severity, timing and impact of these symptoms on your relationships, responsibilities and overall wellbeing.
What Physical Symptoms Can Both Conditions Cause?
Both PMS and PMDD can cause physical symptoms such as bloating, breast tenderness, headaches, cramps, tiredness, sleep problems and changes in appetite. You may also notice fluid retention, muscle or joint aches or changes in your skin.
Physical symptoms alone do not usually distinguish PMS from PMDD. The overall severity and, particularly, the intensity of emotional and behavioural symptoms are more important when assessing whether PMDD may be present.
Can PMS and PMDD Affect Sleep and Concentration?
Both PMS and PMDD can affect your sleep, energy and ability to concentrate in the days before your period. These symptoms may be more disruptive with PMDD and can interfere with your work, studies and everyday responsibilities.
- Difficulty Sleeping: You may struggle to fall asleep, wake during the night or feel that your sleep is less refreshing before your period.
- Daytime Tiredness: Poor sleep and hormonal changes can leave you feeling unusually tired or low in energy during the premenstrual phase.
- Reduced Concentration: You may find it harder to focus, make decisions or complete tasks that normally feel manageable.
- Persistent Symptoms: Sleep or concentration problems that continue throughout the month may suggest another condition also needs to be considered.
Tracking these symptoms alongside your menstrual cycle can help show whether they follow a clear premenstrual pattern. If they remain significant throughout the month, your clinician may assess other possible causes such as anxiety, depression, anaemia or thyroid problems.
Why Do PMS and PMDD Happen?
The exact causes of PMS and PMDD are not fully understood, but both appear to involve your sensitivity to normal hormonal changes during the menstrual cycle, particularly after ovulation. This means you can experience significant symptoms even when your hormone levels are within the expected range.
The way your brain and body respond to these hormonal changes may also involve neurotransmitters such as serotonin, which influence mood. This may help explain why treatments that affect serotonin can improve severe premenstrual symptoms for some people.
Are PMDD Symptoms Psychological or Hormonal?
PMDD is not purely psychological or hormonal. Your symptoms follow the hormonal changes of your menstrual cycle, but they can affect your mood, thoughts, behaviour and physical wellbeing in very real ways.
Treatment may therefore involve both gynaecological and mental health approaches. Hormonal treatments can help reduce the cyclical trigger, while antidepressants or psychological therapy may help manage emotional and behavioural symptoms.
How Are PMS and PMDD Diagnosed?
There is no single blood test or ultrasound that confirms PMS or PMDD. Your clinician will look at your symptoms, their severity, when they occur during your cycle and how much they affect your daily life.
You may be asked about your mood, physical symptoms, sleep, appetite, work and relationships, while other possible conditions are considered. PMDD has stricter diagnostic criteria, so keeping a daily symptom record over several cycles can help provide a clearer picture.
Why Do You Need a Symptom Diary?
A daily symptom diary can help you and your clinician see whether your symptoms consistently follow your menstrual cycle. You should record both physical and emotional symptoms every day for at least two consecutive cycles, rather than only noting the difficult days.
Include the severity of each symptom and how it affects your work, relationships or daily activities. Continuing the diary after starting treatment can also help show whether your symptoms are improving consistently across several cycles.
What Conditions Can Look Like PMS or PMDD?
Anxiety and depression can cause symptoms similar to PMS or PMDD, including low mood, irritability, poor concentration, sleep changes and tiredness. However, these conditions usually continue outside the premenstrual phase, although they may become worse before your period.
Other conditions such as perimenopause, thyroid problems and anaemia can also cause overlapping symptoms. You may also have premenstrual exacerbation, where an existing condition becomes worse before your period, so identifying the underlying cause is important for choosing the right treatment.
Myth vs Fact
| Myth | Fact |
| PMS and PMDD are completely unrelated conditions. | They are closely related premenstrual disorders with overlapping symptoms, although PMDD has stricter diagnostic criteria and greater functional impact. |
| PMDD simply means worse cramps or bloating. | Severe emotional and behavioural symptoms are particularly important in PMDD, although physical symptoms can also occur. |
| A hormone blood test can confirm PMS or PMDD. | Diagnosis depends mainly on the cyclical timing and pattern of symptoms rather than one blood test. |
| One difficult month is enough to diagnose PMDD. | Formal confirmation generally uses prospective daily symptom ratings across at least two symptomatic cycles. |
| Depression throughout the entire month is automatically PMDD if it worsens before a period. | An existing mental-health condition can worsen before menstruation, which may represent premenstrual exacerbation rather than PMDD. |
| Antidepressants are only useful if you have depression throughout the month. | SSRIs can specifically reduce premenstrual symptoms and may sometimes be used only during the premenstrual phase. |
| Lifestyle changes should be enough for severe PMDD. | Healthy routines can support treatment, but severe PMDD may require medical and mental-health care. |
| GnRH treatment permanently stops ovarian function. | GnRH analogues cause temporary and reversible ovarian suppression; permanent surgical menopause is a different treatment. |
Can Lifestyle Changes Help Both PMS and PMDD?
Regular exercise, enough sleep, balanced meals and stress-management techniques may help reduce some PMS and PMDD symptoms. You may also find yoga, mindfulness or relaxation techniques useful, particularly when stress makes your symptoms harder to manage.
Lifestyle measures may improve symptoms for some people but should not be presented as sufficient treatment for everyone with severe PMDD. You can use healthy routines alongside medical treatment and track your symptoms to see whether specific changes genuinely improve how you feel.
Can Cognitive Behavioural Therapy Help?
Cognitive behavioural therapy (CBT) can help you manage troublesome PMS or PMDD symptoms by identifying patterns in your thoughts, emotions and behaviour. It does not mean that your symptoms are imagined; instead, it gives you practical strategies for managing mood changes, stress and their effect on daily life.
You can use CBT on its own or alongside medication, depending on your symptoms. For PMDD, it may be particularly helpful when emotional changes are affecting your relationships, confidence or ability to cope with everyday stress.
How Are Antidepressants Used for PMS and PMDD?
Selective serotonin reuptake inhibitors (SSRIs) are commonly used for severe PMS and can be particularly helpful for PMDD. Depending on your symptoms, your doctor may recommend taking them only during the premenstrual phase or continuously throughout the month.
Possible side effects include nausea, sleep changes, tiredness and reduced sexual interest. Do not stop an antidepressant suddenly without medical advice, and discuss your treatment with your healthcare professional if you are pregnant or planning a pregnancy.
Can Hormonal Contraception Help?
Combined hormonal contraception can help some people manage premenstrual symptoms. Drospirenone-containing combined pills have evidence for premenstrual disorders and may be considered when medically suitable, while your clinician may recommend continuous or extended use depending on your symptoms.
The combined pill can also provide contraception if you need it, but it is not suitable for everyone. Your clinician will consider factors such as blood-clot risk, smoking, migraine with aura, blood pressure and your wider medical history before prescribing it.
What Treatments Are Used When Symptoms Are Severe?
If SSRIs, hormonal contraception and CBT have not helped enough or are unsuitable, you may be offered specialist treatment with GnRH analogues, which temporarily and reversibly suppress ovarian function. These medicines can cause menopausal symptoms such as hot flushes and vaginal dryness and may affect bone density with longer-term use. If treatment continues for more than six months, HRT may be recommended to help protect bone health and reduce menopausal symptoms, with bone-density monitoring considered during prolonged treatment.
In exceptional cases with severe symptoms, surgical treatment may be considered when other appropriate treatments have failed. This causes permanent surgical menopause, so the risks, benefits, alternatives and implications of HRT should be discussed carefully with your specialist. RCOG advises a 3–6-month trial of GnRH analogues with HRT before surgery to help assess the likely effects of ovarian suppression and whether HRT is suitable.
UK Guidance Note
NHS guidance recommends seeing a GP when premenstrual symptoms affect daily life or do not improve sufficiently with lifestyle changes. If symptoms continue despite treatments such as hormonal medication, CBT or antidepressants, referral to a specialist may be appropriate; this may include a gynaecologist, psychiatrist or counsellor according to the symptoms involved.
RCOG also supports specialist management for severe symptoms when first-line treatments have not worked or are unsuitable, particularly if ovarian-suppressing treatment or surgical options are being considered.
When Does PMDD Need Urgent Mental Health Help?
PMDD can sometimes cause severe depression, hopelessness or suicidal thoughts before your period. You should take these symptoms seriously, even if they usually improve once your period begins.
If you feel unable to keep yourself safe or there is an immediate risk to life, call 999 or go to A&E. If you need urgent mental-health support but there is no immediate danger, use NHS 111 online or call 111 and select the mental health option. For recurring severe mood symptoms that are not urgent, arrange a prompt review with your GP.
When Should You See a Gynaecologist?
You can speak to your GP when PMS or PMDD symptoms are affecting your daily life or lifestyle changes have not helped enough. Your GP can review your symptom diary, consider other causes and discuss treatments such as hormonal contraception, CBT or antidepressants.
Your GP can begin the assessment and discuss initial treatment options. Specialist referral may be appropriate if your symptoms remain severe, the diagnosis remains uncertain or initial treatments have not helped enough. Depending on your symptoms, care may involve a gynaecologist, mental-health professional or both.
Key Takeaways
- PMS and PMDD both cause symptoms linked to the premenstrual phase of the menstrual cycle.
- PMDD involves more severe symptoms and has stricter diagnostic criteria than general PMS.
- Physical symptoms can occur with both conditions, but severe mood and behavioural symptoms are particularly important in PMDD.
- Symptoms should improve after menstruation begins, with a substantially improved part of the cycle.
- There is no single blood test or ultrasound that confirms PMS or PMDD.
- A daily symptom diary for at least two consecutive menstrual cycles can help establish the diagnosis.
- Depression, anxiety or other conditions that persist throughout the month can worsen before menstruation without necessarily being PMDD.
- CBT, SSRIs/SNRIs and hormonal treatments can be used according to symptom severity and individual circumstances.
- GnRH analogues are specialist treatments that temporarily suppress ovarian function and may affect bone health with longer use.
- Surgery is reserved for exceptional cases with severe symptoms after other appropriate treatments have failed.
- Suicidal thoughts or concern that you may harm yourself require immediate emergency help rather than waiting for your period or a routine appointment.
Frequently Asked Questions
1. What is the difference between PMS and PMDD?
Premenstrual syndrome (PMS) can cause physical, emotional and behavioural symptoms before your period, while premenstrual dysphoric disorder (PMDD) involves more severe symptoms that can significantly affect your daily life, relationships or work.
2. Is PMDD just a severe form of PMS?
PMDD is often described as a severe form of PMS, but it has specific diagnostic criteria. It is particularly associated with severe emotional and behavioural symptoms, significant effects on everyday functioning and a clear cyclical pattern linked to the menstrual cycle.
3. How are PMS and PMDD diagnosed?
There is no single blood test or ultrasound that confirms either condition. Your clinician usually looks at the timing, severity and impact of your symptoms, with a daily symptom diary over at least two menstrual cycles helping to identify a consistent pattern.
4. Can PMS and PMDD be treated?
Yes. Treatment may include lifestyle changes, cognitive behavioural therapy (CBT), hormonal contraception or selective serotonin reuptake inhibitors (SSRIs), depending on the severity and type of symptoms. More severe cases may require specialist treatment.
5. When should you see a gynaecologist for PMS or PMDD?
You should speak to your GP when PMS or PMDD symptoms regularly interfere with your daily life or have not improved with initial measures. Specialist assessment may be appropriate if symptoms remain severe, the diagnosis is uncertain or initial treatments have not helped enough.
Final Thoughts: What Can You Expect from PMS and PMDD Treatment?
Understanding whether you are experiencing PMS or PMDD can help you find the right support rather than simply accepting severe premenstrual symptoms as something you have to live with. If your symptoms regularly affect your mood, relationships, work or daily activities, keeping a symptom diary and discussing your concerns with a healthcare professional can help you identify the pattern and explore suitable treatment options.
If you’re considering PMS treatment in London, you can contact Gynaecology Clinic London to arrange a consultation with one of our consultant gynaecologists.
References:
- Royal College of Obstetricians and Gynaecologists (RCOG) (2018). Managing premenstrual syndrome (PMS). Available at: https://www.rcog.org.uk/for-the-public/browse-our-patient-information/managing-premenstrual-syndrome-pms/
- Green, L.J., O’Brien, P.M.S., Panay, N. and Craig, M. (2017). Management of Premenstrual Syndrome: Green-top Guideline No. 48. BJOG: An International Journal of Obstetrics & Gynaecology, 124(3), pp. e73–e105. Available at: https://pubmed.ncbi.nlm.nih.gov/27900828/
- NHS (2024). PMS (premenstrual syndrome). Available at: https://www.nhs.uk/conditions/pre-menstrual-syndrome/
- American College of Obstetricians and Gynecologists (ACOG) (2023). Management of Premenstrual Disorders: ACOG Clinical Practice Guideline No. 7. Available at: https://www.acog.org/clinical/clinical-guidance/clinical-practice-guideline/articles/2023/12/management-of-premenstrual-disorders
- Cary, E. and Simpson, P. (2024). Premenstrual disorders and PMDD – a review. Best Practice & Research Clinical Endocrinology & Metabolism, 38(1), 101858. Available at: https://pubmed.ncbi.nlm.nih.gov/38182436/
- NHS (2024). Who can take the combined pill. Available at: https://www.nhs.uk/contraception/methods-of-contraception/combined-pill/who-can-take-it/