PMS: what causes it and what actually helps

Reviewed by Emma Carter, Senior Health & Nutrition Editor

Almost half of women who menstruate notice at least one premenstrual symptom, and about one in five have symptoms bad enough to disrupt daily life. PMS is real and physiological, not a matter of willpower, and several changes have decent evidence behind them.

What PMS is

Premenstrual syndrome describes physical and emotional symptoms that start one to two weeks before your period and usually ease within a day or two of it beginning. The pattern is what defines it: symptoms arrive in the luteal phase, the second half of the cycle, and clear once bleeding starts, then return around the same time next month.

Common symptoms include:

• Physical: bloating, tender breasts, headaches, fatigue, food cravings
• Emotional: mood swings, irritability, anxiety, low mood, poor concentration

Most women have a personal cluster of a few symptoms rather than the whole list.

Why it happens

The exact cause is not settled, but it is closely tied to the hormone changes after ovulation. Estrogen and progesterone rise and fall across the luteal phase, and these shifts affect brain chemicals, especially serotonin, which influences mood, sleep and appetite. Low serotonin activity is thought to drive the premenstrual dip in mood, cravings and sleep.

The strongest clue that hormones are behind it: PMS disappears in pregnancy and after menopause, when the monthly cycle stops.

PMS versus PMDD

There is a severe end of the spectrum called premenstrual dysphoric disorder. The line between the two is largely a matter of which criteria are applied: reported PMS prevalence has ranged from 3.7% to 91.4% depending on the definition used, while PMDD, defined narrowly, sits at 3 to 9% (Indian J Psychiatry, 2016). That is worth knowing before you decide your symptoms are ordinary. In PMDD, emotional symptoms such as depression, anxiety, anger and feeling overwhelmed become intense enough to damage work and relationships. If your premenstrual mood symptoms are severe or you ever feel unsafe, this is not ordinary PMS and needs medical attention, because it responds to specific treatments.

What actually helps

Several lifestyle measures have reasonable support:

• Regular exercise, which improves mood and energy across the cycle
• Cutting back on salt in the second half of the cycle to ease bloating and fluid retention
• Limiting caffeine and alcohol, which can worsen irritability and sleep
• Steady sleep and stress management, since poor sleep amplifies mood symptoms
• Smaller, regular meals with steady carbohydrates to blunt cravings, an approach that overlaps with low-GI eating

Calcium has some evidence for reducing premenstrual symptoms, and a diet built on whole foods and fiber supports steadier energy. Tracking your symptoms across two or three cycles helps you see your own pattern and confirms the timing.

Medical treatment

When lifestyle changes are not enough, doctors have options. Hormonal birth control can smooth out the cyclical hormone swings for some women. For prominent mood symptoms, an SSRI antidepressant can be used, sometimes only in the luteal phase rather than every day. Over-the-counter pain relief helps with cramps and headaches.

When to see a doctor

See your doctor if PMS disrupts your work, relationships or daily life, if symptoms do not respond to lifestyle changes, or if you have severe low mood, anxiety or any thoughts of self-harm. If your main problem is severe period pain rather than premenstrual mood, a condition like endometriosis is worth ruling out. Keeping a symptom diary before the visit makes the diagnosis quicker and the plan more useful.

Frequently asked questions

What is PMS?

Premenstrual syndrome is a mix of physical and emotional symptoms that appear in the one to two weeks before your period and fade once it starts. Common signs include bloating, tender breasts, mood swings, irritability and fatigue. Almost half of people who menstruate report at least one PMS symptom.

What causes PMS?

The exact cause is not fully known, but it is tied to the natural hormone shifts of the second half of the cycle and how they affect brain chemicals like serotonin. Symptoms track with these fluctuations, which is why they disappear during pregnancy and after menopause.

What is the difference between PMS and PMDD?

PMDD is a severe form where emotional symptoms, especially depression, anxiety and anger, are intense enough to disrupt your life and relationships. If your premenstrual mood symptoms are severe, PMDD is worth discussing with a doctor, as it is treated differently.

What helps PMS symptoms?

Regular exercise, limiting salt, caffeine and alcohol, steady sleep, and stress management help many women. Some find calcium and other measures useful. For persistent or severe symptoms, doctors may suggest hormonal birth control or, for mood symptoms, an SSRI.

References

1. Premenstrual dysphoric disorder: general overview, treatment strategies, and focus on sertraline · Indian Journal of Psychiatry, 2016
2. Premenstrual syndrome (PMS): symptoms and treatment · Cleveland Clinic
3. Premenstrual syndrome (PMS): symptoms and causes · Mayo Clinic