What is premenstrual syndrome?

A week or two before your period starts, you may notice bloating, headaches, mood swings or other physical and emotional changes. These recurring monthly symptoms are known as premenstrual syndrome, or PMS. About 85% of women experience some degree of PMS. A few have more severe symptoms that disrupt work or personal relationships, known as premenstrual dysphoric disorder (PMDD).

Symptoms of PMS: Cravings

Many women develop specific cravings when PMS strikes, usually for sweet, starchy foods like chocolate cake. The reasons for this are not well understood. Other women may lose their appetite or develop an upset stomach. Bloating and constipation are also common.

Symptoms of PMS: Acne

Acne is one of the most common signs of PMS, and it doesn't just affect teenagers. Hormonal changes can cause glands in the skin to produce more sebum. This oily substance may clog the pores, triggering an outbreak - a visible reminder that your period is on its way.

Symptoms of PMS: Pain

PMS can trigger a wide range of aches and pains, including:

• Back pain
• Headaches
• Tender breasts
• Joint pain

Symptoms of PMS: Mood swings

For many women, the most troubling aspect of PMS is its unpredictable impact on mood. Irritability, anger, crying spells, low mood and anxiety may come and go in the days leading up to your period. Some women even have trouble with memory and concentration during this time.

Who gets PMS?

Any woman who has a period can get PMS, but the following patterns based on age and ethnicity have been observed:

• PMS is more likely in the late 20s to mid-40s.
• Black women report food cravings more than white women.
• White women report mood changes and weight gain more than black women.
• Older teens tend to have more severe PMS than younger teens.
• PMS may be more severe in the 40s.

How PMS affects other conditions

PMS can worsen the symptoms of certain chronic conditions, including:

• Asthma and allergies
• Depression and anxiety
• Seizure disorders
• Migraines

Let your doctor know if your condition gets worse right before your period.

What causes PMS?

The exact cause of PMS is not clear, but we do know that levels of oestrogen and progesterone drop during the week before your period. Many doctors believe this decline in hormone levels triggers the symptoms of PMS. Deficiencies in certain vitamins and minerals may also play a role.

PMS or something else?

The symptoms of PMS can be similar to or overlap with other conditions, including:

• Perimenopause
• Depression or anxiety
• Chronic fatigue syndrome
• Thyroid disease

The key difference is that PMS symptoms come and go in a distinct pattern, month after month.

Diagnosing PMS: Symptom tracker

To figure out whether you have PMS, record your symptoms on a tracking form like this one. You may have PMS if:

• Symptoms occur during the five days before your period.
• Once your period starts, symptoms end within four days.
• Symptoms return for at least three menstrual cycles.

When to seek medical advice

If you have any thoughts of harming yourself, call 999 or seek emergency medical care. You should also seek medical advice promptly if your symptoms are causing problems with your job, personal relationships or other daily activities. This may indicate a more severe form of PMS known as premenstrual dysphoric disorder (PMDD).

Premenstrual dysphoric disorder

Premenstrual dysphoric disorder (PMDD) follows the same pattern as PMS, but the symptoms are more disruptive. Women with PMDD may experience panic attacks, crying spells, suicidal thoughts, insomnia or other problems than interfere with daily life. Fortunately, many of the same strategies that relieve PMS can be effective against PMDD. Risk factors for PMDD include a personal or family history of depression, mood disorders or trauma.

PMS remedy: Exercise

Exercise can help boost your mood and fight fatigue. To get the benefits you need to exercise regularly - not just when PMS symptoms appear. Aim for 30 minutes of moderate physical activity on most days of the week. Vigorous exercise on fewer days can also be effective.

PMS remedy: Diet rich in B vitamins

There's evidence that foods rich in B vitamins may help ward off PMS. In one study, researchers followed more than 2,000 women for 10 years. They found that women who ate foods high in thiamine (pork, Brazil nuts) and riboflavin (eggs, dairy products) were far less likely to develop PMS. Taking a supplement of vitamin B6 may also help but more research is needed.

PMS remedy: Complex carbs

Complex carbohydrates, such as whole-grain breads and cereals, are packed with fibre. Eating plenty of fibre can keep your blood sugar stable, which may reduce mood swings and food cravings. Enriched whole-grain products also contain the B vitamins, thiamine and riboflavin.

PMS remedy: Foods and drinks to avoid

You may be able to reduce PMS symptoms by cutting back on these foods and drinks:

• Salt, which can increase bloating
• Caffeine, which can cause irritability
• Sugar, which can make cravings worse
• Alcohol, which can affect mood

PMS remedy: Stress relief

Because PMS can cause tension, anxiety and irritability, it's important to find healthy ways to cope with stress during this time. Different strategies work for different women. You may want to try yoga, meditation, massage, writing in a journal or simply talking with friends. It also helps to make sure you get enough sleep.

PMS remedy: Over the counter medicines

Over-the-counter pain relievers can ease some of the physical symptoms of PMS, such as breast tenderness, headaches, back pain or cramps. OTC medicines that work well for these symptoms include paracetamol and ibuprofen.

PMS remedy: Hormone treatments

Contraceptive pills prevent ovulation by regulating hormones. This usually leads to lighter periods and may reduce the symptoms of PMS. The NHS says other hormonal treatments may include GnRH analogues, which are synthetic hormones that create a temporary menopause. It says they are only used in women with severe PMS when other treatments have failed.

PMS remedy: Other medications

Women with severe mood swings or PMDD may benefit from antidepressants. The most commonly used drugs are known as SSRIs. However, other types of antidepressants are often prescribed to treat PMDD. Antidepressants may be taken for 10 to 14 days before each period or throughout the menstrual cycle.

PMS remedy: Supplements

The NHS says there are many supplements used for PMS, but little research to back their effectiveness. Most studies show mixed results. The NHS says these complementary therapies may reduce some PMS symptoms:

• Magnesium
• Vitamin B6
• Vitamin E

PMS remedy: Herbal extracts

Herbal remedies such as agnus castus are sometimes used for PMS, but many are not well studied. Agnus castus has been registered by the MHRA as a traditional herbal medicine for PMS symptoms including mood changes and irritability. Check with your doctor before trying these herbs. They may interact with medicines or be harmful for people with certain long-term conditions.

Related reading

• Your guide to PMS
• Oestrogen and your emotions
• Could it be premenstrual dysphoric disorder?
• Things you didn't know about your period
• Your guide to period pain