Premenstrual syndrome (PMS)

What’s PMS?

PMS is the name for various symptoms you might experience in the days or weeks before your period. It happens during the second half of your menstrual cycle — after you ovulate and before you bleed. Symptoms usually go away within a few days of starting your period, and for most people are mild. 

Premenstrual dysphoric disorder (PMDD) is a severe type of PMS that affects 2% of people with periods.

What causes PMS?

Experts aren’t entirely sure what causes PMS. But you might be more sensitive to normal hormonal changes happening in your body, such as your progesterone levels.  

Progesterone is a hormone that helps prepare your body for pregnancy. Your progesterone levels naturally increase after you ovulate and drop before your period.

PMS symptoms

Common PMS symptoms include:

• mood swings
• tummy pain or bloating
• tiredness
• problems sleeping
• changes in your mental health — like feeling anxious, sad or irritable
• breast tenderness
• spotty skin — particularly on your cheeks and jawline
• headaches 
• changes in your appetite
• changes in your sex drive (libido) 
• changes in your behaviour — like binge eating
• feeling overwhelmed and/or out of control
• aching muscles and joints

Being more sensitive to progesterone is thought to alter the brain chemicals which make you feel calm and happy — GABA (gamma-aminobutyric acid) and serotonin. This might be why you feel anxious or sad before your period.

These chemical changes might also reduce your pain tolerance. This could cause symptoms like:

• breast tenderness
• bloating
• joint and muscle pain

Or it could be that those body parts are more sensitive to your hormones.

Tummy pain (uterine cramps) is thought to be caused by increased levels of prostaglandins, a chemical that makes your uterus contract. Lots of contractions can mean that less blood reaches your muscles, making your pain worse.

You might be able to help improve your PMS symptoms by taking magnesium supplements. But you should check with your GP first before starting a new supplement.

PMDD symptoms

PMDD symptoms are like PMS symptoms, but much more serious. They're severe enough to seriously disrupt your everyday life — like socialising, work, school, and relationships. As well as PMS, your symptoms might include:

• feeling hopeless
• depression
• severe anxiety
• mood swings
• suicidal feelings
• feeling angry and irritable

If you’re having suicidal thoughts, you can call the Samaritans for free on 116 123. 

Find out more about how to support your mental wellbeing.

Why are my periods irregular?

You have irregular periods if the gap between them keeps changing — sometimes this results from coming off the contraceptive pill. Irregular periods can also be a sign of a hormonal imbalance or polycystic ovary syndrome (PCOS).

Irregular periods don’t always mean you have a health problem — menstrual cycles differ from person to person. But if you're worried about the length of your menstrual cycle, it’s a good idea to investigate this further with your GP.

Is there treatment for PMS?

There are things you can do to manage your PMS symptoms at home, including:

• getting plenty of sleep
• regular exercise
• avoiding alcohol
• stopping smoking
• taking painkillers — like ibuprofen and paracetamol
• meditation or yoga to manage stress

But if these don’t work and PMS is affecting your everyday life, you should see a GP. They might refer you to a specialist, like a gynaecologist to talk about your options.

Your GP or specialist might recommend:

• hormonal treatment  — like the combined pill
• antidepressants — like selective serotonin reuptake inhibitors (SSRIs)
• dietary supplements — like magnesium
• talking therapy

If your symptoms are very serious, your doctor might suggest treatments that lead to temporary menopause. These are called gonadotropin-releasing hormone (GnRH) analogues.

In very severe cases, a specialist might talk to you about having an oophorectomy – an operation to remove your ovaries. This could be with or without a total hysterectomy — an operation to remove your womb (uterus). You can’t get pregnant after a total hysterectomy, so they’ll only consider this if your symptoms are really severe.

Are there supplements for PMS?

Eating a balanced diet of a wide range of foods is the best way to support your overall health. 

But according to some studies, supplements can also help ease PMS symptoms, including:

• magnesium
• vitamin B6
• calcium
• vitamin D

Some supplements claim to treat PMS, but there’s mixed evidence as to whether or not they work.

Vitamin D

Vitamin D helps your reproductive system function properly. It also regulates hormone fluctuations and your calcium levels. Your neurotransmitters need vitamin D to function as they should.

Studies have found that people with PMS have lower vitamin D levels during this part of the menstrual cycle, compared to people without PMS. Low vitamin D levels are thought to make your PMS symptoms worse. 

So it might be helpful to eat foods rich in vitamin D — like oily fish and egg yolks. Some foods are also fortified with vitamin D, including cereals and spreads. 

Our body creates vitamin D from sunlight. So during winter, when there’s less sunshine, it’s a good idea to take vitamin D supplements. 

Calcium

Calcium helps your brain communicate with itself and your muscles.

According to studies, people with less calcium in their diets have worse PMS symptoms — like low mood and problems sleeping.

You can boost the calcium in your body by eating foods like milk, cheese, and kale. Non-dairy products with added calcium like oat and soya drinks are a good choice too.

Find out more about the role of vitamins and minerals.

Magnesium

Magnesium helps to keep your nervous system working properly. 

Studies show magnesium supplements can help reduce PMS symptoms — like stress, anxiety, bloating and breast tenderness.

So it’s important to eat foods rich in magnesium, like nuts, seeds, spinach, and wholemeal bread.

You can also take magnesium supplements, but it’s important to speak to your GP first to ensure you take the correct dosage.