Premenstrual syndrome (PMS) affects more than 85% of women at some point in their lives. It refers to a group of physical and emotional symptoms that appear after ovulation and before the first day of your period. For some women, these symptoms are mild. For others, they interfere with daily life, work, and relationships. This article explains what causes PMS, what symptoms to watch for, and when it is time to speak with a healthcare provider.
What Is Premenstrual Syndrome?
Premenstrual syndrome is a pattern of symptoms that appears during the luteal phase of the menstrual cycle. This is the phase between ovulation (around day 14) and the start of your period. The symptoms then disappear once menstruation begins.
Most women experience at least one or two symptoms during this time. However, when those symptoms are strong enough to disrupt your normal routine, the condition is called PMS. It is important to know that PMS only occurs in women who ovulate.
Women who do not ovulate — due to pregnancy, menopause, or certain birth control pills — do not experience PMS. However, they may still notice hormone-related changes throughout their cycle.
How Common Is PMS in Canada?
PMS is very common. According to Mayo Clinic’s overview of premenstrual syndrome, up to 3 in 4 women report some form of PMS during their reproductive years. Symptoms can begin as early as the late teens or early twenties. Some women first notice PMS in their thirties.
Symptoms can also change over time. Many women find that PMS worsens as they approach perimenopause, which typically begins in the late thirties or early forties.
What Causes Premenstrual Syndrome?
Researchers do not fully understand what causes premenstrual syndrome in some women but not others. The hormonal system involved in the menstrual cycle is complex, and multiple factors appear to play a role.
One clear factor is genetics. Most women with PMS have a close female relative — a mother, sister, or aunt — who also experiences it. This suggests a hereditary link.
Hormonal Factors That Contribute to PMS
Several hormonal changes during the menstrual cycle can trigger PMS symptoms. These include:
High aldosterone levels: This hormone, produced by the adrenal glands, rises naturally after ovulation. It can cause fluid retention, breast swelling, weight gain, and headaches in some women.
Excess prolactin: Produced by the pituitary gland, too much prolactin can interfere with ovulation and cause irregular periods.
Low serotonin use: Serotonin is a brain chemical that affects mood. Some women with PMS are more sensitive to normal hormonal shifts. As a result, their brains may not use serotonin effectively, leading to anxiety and depression.
Low endorphin levels: Endorphins are natural pain-relieving chemicals also made by the pituitary gland. When levels drop, women may feel more depressed and more sensitive to pain.
Prostaglandins: These are substances released by cells throughout the body. They can cause breast tenderness, fluid retention, cramps, headaches, irritability, and low mood.
Insulin sensitivity changes: Blood sugar regulation can shift during the premenstrual phase. Some experts believe that low blood sugar (hypoglycaemia) may contribute to PMS symptoms in certain women.
Because symptoms vary so widely between women, it is likely that different combinations of these factors are at play for each individual.
Common Symptoms of Premenstrual Syndrome
There are more than 150 documented symptoms of premenstrual syndrome. However, most women experience only a handful of them. Symptoms can range from mild to severe and may differ from one cycle to the next.
Many women also report that stress — whether emotional or physical — makes their symptoms worse. Furthermore, symptoms may appear throughout the entire luteal phase, or only for a few days just before the period starts.
Physical Symptoms
Breast swelling and tenderness
Bloating, fluid retention, and temporary weight gain
Changes in bowel habits, such as constipation or diarrhoea
Breast discharge when the nipple is pressed (any discharge that occurs without pressing should be checked by a doctor)
Strong food cravings, especially for sweets or salty foods
Changes in sleep patterns
Fatigue and low energy
Decreased sex drive
Headaches, muscle aches, joint pain, and lower back pain
Emotional and Behavioural Symptoms
Sadness, hopelessness, or depression
Anger and irritability
Sudden mood swings
Difficulty concentrating or staying focused
Withdrawing from family, friends, or social activities
It is worth noting that the severity and pattern of these symptoms can change month to month. They may seem to come and go without a clear reason, which can be confusing and frustrating.
What Is PMDD? A More Severe Form of PMS
Some women experience a much more intense version of premenstrual syndrome called premenstrual dysphoric disorder (PMDD). PMDD involves severe mood disturbances, including serious depression, extreme irritability, and intense anxiety.
These symptoms go beyond typical PMS. They can make it very difficult to function at work, at home, or in relationships. PMDD is a recognised medical condition and can be treated. If you think you may have PMDD, speaking with your family doctor is an important first step.
You can learn more about PMDD from Healthline’s guide to premenstrual dysphoric disorder.
How to Track and Manage PMS Symptoms
One of the most helpful things you can do is track your symptoms over two or three cycles. Write down when they start, how strong they are, and when they stop. This record helps your doctor confirm a diagnosis of premenstrual syndrome and rule out other conditions.
Lifestyle Changes That May Help
Several everyday changes can reduce the impact of PMS symptoms. These include:
Regular exercise: Physical activity helps regulate mood and reduces bloating and fatigue.
A balanced diet: Eating more fibre, fruits, and vegetables — while cutting back on salt, sugar, caffeine, and alcohol — can ease many symptoms.
Consistent sleep: Going to bed and waking up at the same time every day supports hormonal balance.
Stress management: Techniques like deep breathing, yoga, or mindfulness can lower the emotional impact of PMS.
Reducing caffeine and alcohol: Both substances can worsen mood swings, breast tenderness, and sleep problems.
Medical Treatments Available in Canada
If lifestyle changes are not enough, your doctor may suggest medical options. These can include antidepressants (especially SSRIs), hormonal birth control, or other prescription medications. Health Canada oversees the approval of medications used to treat hormone-related conditions in Canada.
Most provincial health plans cover visits to your family doctor to discuss PMS treatment. If you do not have a family doctor, a walk-in clinic can be a good starting point for getting assessed and referred.
When to See a Doctor About PMS
You should speak with a healthcare provider if your premenstrual syndrome symptoms are affecting your daily life. This includes missing work or school, avoiding social activities, or feeling unable to cope emotionally in the week or two before your period.
See your family doctor or visit a walk-in clinic if you experience:
Severe depression or feelings of hopelessness
Thoughts of harming yourself
Extreme mood swings that affect your relationships
Symptoms that do not improve after trying lifestyle changes
Breast discharge that occurs without pressing on the nipple
Symptoms that get worse each cycle
Your doctor can help rule out other conditions, such as thyroid disorders or clinical depression, that may be making your symptoms worse. Always consult a qualified healthcare professional before starting any new treatment for PMS.
Frequently Asked Questions About Premenstrual Syndrome
What is the difference between PMS and PMDD?
Premenstrual syndrome (PMS) refers to a range of physical and emotional symptoms before your period. PMDD, or premenstrual dysphoric disorder, is a severe form of PMS that causes intense depression, anxiety, and mood swings that significantly disrupt daily life. Both conditions are treatable, so speak with your doctor if you think you may have either one.
When do PMS symptoms usually start and stop?
Premenstrual syndrome symptoms typically begin after ovulation, around day 14 of the cycle, and last until the first day of your period. Some women only experience symptoms for a few days before their period starts. The timing can vary from cycle to cycle.
Can PMS get worse with age?
Yes, premenstrual syndrome symptoms can worsen as women approach perimenopause, which often begins in the late thirties or early forties. Hormonal fluctuations tend to become more pronounced during this time. Talking to your family doctor can help you manage changing symptoms as you get older.
Does the birth control pill help with PMS?
Hormonal birth control pills can reduce PMS symptoms in some women by regulating hormone levels throughout the cycle. However, they do not work the same way for everyone, and some women find their symptoms stay the same or change. Ask your doctor or walk-in clinic provider whether hormonal birth control is right for your situation.
What foods should I avoid if I have PMS?
Women with premenstrual syndrome are often advised to reduce salt, sugar, caffeine, and alcohol in the two weeks before their period. These substances can worsen bloating, mood swings, breast tenderness, and sleep problems. Eating more fibre-rich foods and staying well hydrated may help ease symptoms.
Is PMS covered under Canadian provincial health plans?
Yes, visits to a family doctor or walk-in clinic to discuss premenstrual syndrome are generally covered under provincial health plans across Canada. Prescription treatments, such as antidepressants or hormonal medications, may also be covered depending on your province and specific drug plan. Check with your provincial health authority for details.
Key Takeaways
Premenstrual syndrome affects over 85% of women at some point in their lives.
Symptoms appear after ovulation and disappear when menstruation begins.
Common symptoms include bloating, breast tenderness, mood swings, fatigue, and irritability.
Causes are linked to hormonal changes, genetics, and brain chemistry — particularly serotonin levels.
PMDD is a more severe form of PMS that requires medical attention.
Lifestyle changes such as regular exercise, a fibre-rich diet, and stress management can help.
If symptoms affect your daily life, speak with your family doctor or visit a walk-in clinic.
Most PMS-related doctor visits are covered by provincial health plans in Canada.
Always consult a healthcare professional before starting any new treatment.
