COVID-19 Information - To see our up to date advice for using our pharmacies - Click Here

Health Knowledge and Encyclopedia

At your local Pearn's Pharmacy we can offer advice on most general health matters. You can also use our Health Encyclopaedia to provide you with the tools and links you need to pinpoint symptoms and get a full explanation of a suspected condition.

Search By Letter
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y |

Search by Keyword

Premenstrual syndrome


Premenstrual syndrome (PMS) is the name given to the physical, psychological and behavioural symptoms that can occur in the two weeks before a woman's monthly period. It is also known as premenstrual tension (PMT).

There are many different symptoms of PMS, but typical examples are fluid retention, breast tenderness, mood swings, feeling irritable and loss of interest in sex.

These symptoms usually improve when the period starts, and they disappear a few days afterwards.

Nearly all women of child-bearing age have some premenstrual symptoms, but women aged between their late 20s and early 40s are most likely to experience PMS.

Premenstrual dysphoric disorder (PMDD)

A small number of women find that their symptoms are severe enough to stop them living their normal lives. This is due to a more intense type of PMS known as premenstrual dysphoric disorder (PMDD).

If you are finding it difficult to deal with the symptoms of PMS, see your GP. They can help to determine if you have PMDD, and may be able to offer you treatment to manage the symptoms you're experiencing.

Read more about how PMS is diagnosed.

Why it happens

The exact cause of PMS is not fully understood. However, it is thought to be linked to the changing levels of hormones in the body during a woman's menstrual cycle.

Certain lifestyle factors such as lack of exercise, stress and eating a poor diet are also thought to aggravate the symptoms of PMS.

Read more information about the causes of PMS.

Managing PMS symptoms

There is no cure for PMS, but the symptoms can often be managed with treatment. This may include medication, hormone or psychological treatments.

Certain lifestyle changes can also help to manage symptoms. These includes:

PMS usually improves after the menopause

^^ Back to top


There are many different symptoms of premenstrual syndrome (PMS), which can vary from person to person and change slightly every month.

For example, you may find that you have similar PMS symptoms every month but they vary in intensity. Or you may have slightly different symptoms every few months. PMS tends to be different for every woman.

The symptoms of PMS usually happen at the same time in your menstrual cycle each month, which can be up to two weeks before your period starts. They usually improve once your period has started, and then disappear until your cycle starts again.

Common symptoms

More than 100 different symptoms of PMS have been recorded, but the most common are listed below.

Physical PMS symptoms

  • fluid retention and feeling bloated
  • pain and discomfort in your abdomen (tummy)
  • headaches 
  • changes to your skin and hair
  • backache
  • muscle and joint pain
  • breast tenderness
  • insomnia (trouble sleeping)
  • dizziness
  • tiredness
  • nausea
  • weight gain (up to 1kg)

Psychological PMS symptoms

  • mood swings
  • feeling upset or emotional
  • feeling irritable or angry
  • depressed mood
  • crying and tearfulness
  • anxiety 
  • difficulty concentrating
  • confusion and forgetfulness
  • restlessness
  • decreased self-esteem

Behavioural PMS symptoms

  • loss of libido (loss of interest in sex)
  • appetite changes or food cravings

Any chronic (long-term) illnesses, such as asthma or migraine, may get worse.

Premenstrual dysphoric disorder

While most women with PMS find their symptoms uncomfortable, a small percentage have symptoms that are severe enough to stop them living their normal lives. This is due to a more intense type of PMS, known as premenstrual dysphoric disorder (PMDD).

The symptoms of PMDD are similar to those of PMS, but more exaggerated and often have more psychological symptoms than physical ones. They can include:

  • feelings of hopelessness
  • persistent sadness or depression
  • extreme anger and anxiety
  • decreased interest in usual activities
  • sleeping much more or less than usual
  • very low self-esteem
  • extreme tension and irritability

As depression is a common symptom of PMDD, it is possible that a woman with PMDD may have thoughts about suicide.

PMDD can be particularly difficult to deal with because it can have a negative effect on your daily life and relationships. See your GP if you are experiencing severe symptoms.

Read more about treating PMS and PMDD.

^^ Back to top


The exact cause of premenstrual syndrome (PMS) is not fully understood, but various possible factors may contribute to the symptoms.

These are described below.

Hormone changes

During your menstrual cycle, levels of hormones such as oestrogen and progesterone rise and fall. Hormone changes are thought to be the biggest contributing factor to many of the symptoms of PMS. The fact that PMS improves during pregnancy and after the menopause, when hormone levels are stable, supports this theory.

Chemical changes

Like your hormone levels, certain chemicals in your brain, such as serotonin, fluctuate during your menstrual cycle. Serotonin is known to help regulate your mood and make you feel happier, so it is possible that women with low levels of serotonin are particularly sensitive to the symptoms of PMS. Low levels of serotonin may also contribute to symptoms such as:

  • tiredness
  • food cravings
  • insomnia (difficulty sleeping)

Lifestyle factors

Weight and exercise

Research has shown that you are more likely to have PMS if you are obese (with a body mass index of more than 30) and if you do little exercise.

Read more about calculating your BMI and health and fitness.


You may find that your symptoms of PMS get worse as you become more stressed. While it is not a direct cause, stress can aggravate the symptoms of PMS.

Read more about how to manage stress.


Eating too much of some foods and too little of others may also contribute to PMS symptoms. For example, too much salty food may add to fluid retention and make you feel bloated. Alcohol and caffeinated drinks can disrupt your mood and energy levels. Low levels of vitamins and minerals may also make your PMS symptoms worse.

Read more about maintaining a balanced diet.

^^ Back to top


There is no test or procedure that can diagnose premenstrual syndrome (PMS), but if you are finding your symptoms difficult to deal with, see your GP.

In order to identify exactly what symptoms you have and how severe they are, your GP may ask you to use a diary or chart to record how you're feeling each day in the run-up to your period. You may have to do this for at least two months so that your GP can monitor any possible symptom patterns.

Premenstrual dysphoric disorder

If you think you may have premenstrual dysphoric disorder (PMDD), see your GP.

To determine whether you have PMDD, and to rule out other conditions, your GP may:

  • ask you about your symptoms and carry out a medical examination
  • perform tests such as a blood test or urine test
  • refer you to a mental health specialist

They may also be able to suggest specific treatments to relieve your symptoms.

PMDD is only diagnosed when your mood symptoms seriously affect your relationships and stop you from functioning properly at work or school.

Read more about treating PMS and PMDD.

^^ Back to top


There is no cure for premenstrual syndrome (PMS) but there are treatments that can help you manage your symptoms so they do not interfere with your daily life.

However, if your PMS is mild or moderate, you may want to make changes to your diet and lifestyle before resorting to medical treatment. This is because many of the medical treatments can have side effects that may be worse than your PMS symptoms.

Lifestyle changes


The following tips can help you to maintain a healthy, balanced daily diet:

  • Eat smaller meals more frequently to help reduce bloating.
  • Avoid eating salty foods to limit bloating and fluid retention.
  • Drink plenty of water to avoid dehydration – being dehydrated can make headaches and tiredness worse.
  • Eat lots of complex carbohydrates, which can be found in foods such as fruit, vegetables and wholegrains.
  • Eat calcium-rich foods, such as cheese and milk, to improve physical and psychological symptoms of PMS. If you can't eat dairy products, try calcium-fortified soya alternatives.
  • Avoid caffeine and alcohol, which can affect your mood and energy levels.
  • Eat plenty of fruit and vegetables, which are rich in vitamins and minerals, and may ease your PMS symptoms. Aim to eat at least five portions a day.

Read more information about healthy eating.


If possible, aim to do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity every week. Examples of activities include walking, swimming and cycling. Exercise improves your overall health and can help to alleviate depression and tiredness.

Stretching and breathing exercises, such as yoga and pilates, can help you sleep better and reduce your stress levels.

Read more about health and fitness and how to manage stress.

Complementary medicines

There are many non-prescribed alternative treatments and supplements for PMS, and many women find them helpful in easing their symptoms. However, there is little research to back up their effectiveness. Most of the existing studies have shown mixed results.

Examples of complementary therapies that may reduce some symptoms of PMT are vitamins and minerals such as magnesium, vitamin B6 and vitamin E.

Always see your GP before taking any complementary medicine or supplement. If you decide to take a complementary treatment, take one at a time so you know if it works for you. If your symptoms don't change after three months, go back to your GP, who may recommend another treatment.

Psychological therapy

If you have psychological symptoms, such as feeling depressed or emotional, it may help to talk to a health professional. Cognitive behavioural therapy (CBT) is the term for a group of therapies that are designed to help solve problems such as anxiety and depression. A cognitive behavioural therapist can help you learn new ways of managing some of your symptoms.

Read more about cognitive behavioural therapy.

Medical treatment

If your PMS is severe or you have premenstrual dysphoric disorder (PMDD), you may wish to try a medical treatment. However, there is no single treatment that works for everyone.

A wide range of treatments are available. You may have to try several before you find one that suits you. Your choice of treatment will be based on your symptoms and how severe they are, and the possible side effects of the medication.

If your GP prescribes you a treatment for PMS, they may ask you to record any changes to your symptoms so that you both know how effective it is for you. If the treatment doesn't ease your symptoms, your GP may prescribe an alternative.

Medical treatments for PMS include:

These are described in more detail below.

Non-steroidal anti-inflammatory drugs (NSAIDs)

You can take NSAIDs, such as ibuprofen and aspirin, to ease stomach cramps and sore breasts. They may also relieve headaches, muscle pain and joint pain, but they can make fluid retention worse.

Children under the age of 16 shouldn't take aspirin. If you have asthma, do not take ibuprofen.


As well as preventing pregnancy, some types of contraception can be prescribed to regulate symptoms of PMS. They often work by stopping ovulation (when an egg is released from your ovaries) or stabilising hormone levels, which can help to control mood swings. These include:

However, not all these forms of contraception work for all women with PMS, and they can have side effects. The side effects can be similar to the symptoms of PMS and may include, for example, fluid retention and irritability.

Selective serotonin reuptake inhibitors (SSRIs)

Selective serotonin reuptake inhibitors (SSRIs) may be the most effective treatment if you have severe PMS or PMDD. SSRIs, such as fluoxetine and sertraline, are antidepressants that can be taken daily to relieve tiredness, food cravings, sleep problems and combating depression.

However, like oral contraceptives, SSRIs may have negative side effects that may outweigh their benefits, such as nausea, insomnia, headache and loss of libido (less interest in sex).

Gonadotrophin-releasing hormone analogues

Gonadotrophin-releasing hormone (GnRH) analogues are synthetic hormones that create a temporary menopause and stop your periods by blocking the production of oestrogen and progesterone. They are taken as an injection and work in a similar way to gonadotrophin-releasing hormone (which is a natural female hormone).

GnRH analogues should only be used in women with severe PMS when all other treatments have failed. They often have side effects, such as hot flushes, vaginal dryness and loss of libido.

Drug names include goserelin, nafarelin and leuprorelin.

^^ Back to top
“Pearn's Pharmacies, putting patients first”

Pearn's Pharmacy Services

Common Ailment Service

Primary Choice is a campaign to help the public choose the right health advice in the community.

Tell Me More


Repeat, one-off prescriptions. Collect in store or home delivery.

Sign Up

Funded Services

Browse our NHS funded services offered in our stores.

See Services


We are receiving an increase in the number of requests for delivery of medicines due to the COVID-19 pandemic.

Important Info

Find a GP   

Use our GP locator service and nearest Pearn's Pharmacy Branch

Search Now