Symptoms of PMS start one to two weeks before the onset of menstruation, and go away when the period starts, or soon afterwards. There are many symptoms that may occur as part of PMS including:

• Fatigue, sometimes with excessive sleepiness (hypersomnia)
• Food cravings (especially for chocolate, sweet and salty foods) and appetite changes
• Bloating and fluid retention, which may lead to weight gain, and can cause swelling of the fingers, abdomen and ankles
• Breast tenderness and pain
• Headaches, backaches, muscle aches and joint pain
• Uterine cramping
• Depressed mood, anxiety and crying spells
• Mood swings, irritability, hostility, tension, anger
• Feeling overwhelmed
• Poor concentration
• Insomnia and disturbed sleep
• Acne, oily skin and/or oily hair
• Digestive disturbances, such as diarrhoea or constipation
• Libido changes
  

It is common for menstruating women to experience premenstrual symptoms of some sort. In approximately 40% of them, the symptoms are significant enough be classified as PMS. A smaller percentage of women experience a severe form of the condition called premenstrual dysphoric disorder (PMDD) in which physical symptoms are accompanied by debilitating emotional symptoms such as severely depressed mood, low self-esteem, hopelessness, anger, and difficulty concentrating.

It is not clear why some women are affected by PMS and others are not, or how the symptoms of PMS are caused. However, PMS is believed to largely occur as a result of the changes in the levels of oestrogen and progesterone that occur during the luteal phase of the menstrual cycle, which commences at the time of ovulation (usually the 14th day after the start of menstruation if your cycle is 28 days).

Other hormones may also be involved (for example, some symptoms, such as breast tenderness, have been linked to an excess of prolactin, a hormone that stimulates the production of breast milk).

Mineralocorticoids are a group of hormones that regulate the body’s fluids. Changing levels of these hormones may cause the fluid retention and bloating that many women experience. Similarly, hormonal imbalance may affect levels of neurotransmitters such as serotonin, and this may lead to emotional symptoms such as anxiety and depressed mood.

The symptoms of PMS may be aggravated by a wide range of factors, including stress, genetics, the number of children you’ve had, underlying physical or health problems (e.g. underactive thyroid, depression), and exposure to compounds called xeno-estrogens, which are present in our environment (e.g. from some pesticides).

Additionally, a number of dietary factors appear to influence PMS symptoms. These include:

• High dietary intake of salt, which is especially linked to fluid retention
• Consumption of excessive quantities of sugar, alcohol and/or caffeine, which are linked to disturbed moods and energy problems. Blood sugar imbalance may also be a factor for some women.
• High fat diets, especially those high in saturated fat
• Low intake of magnesium and calcium

Regular exercise appears to offer a degree of protection from PMS, and is associated with less susceptibility to both emotional and physical symptoms.

• In traditional western herbal medicine, Vitex agnus-castus is used to help normalise heavy, absent or irregular periods and relieve PMS symptoms such as breast tenderness and fluid retention.
• Taking vitamin B6 may help relieve PMS symptoms, including breast tenderness, fluid retention and mood changes.
• Low calcium and magnesium levels have been associated with PMS. Calcium supplementation may improve overall PMS symptoms, including mood problems, fluid retention and pain. Magnesium helps relieves cramps and spasms, and may be beneficial in times of stress. It is recommended that calcium and magnesium be taken together, sometimes with additional vitamin B6.
• St. John’s wort relieves feelings of low mood, despondency, sadness, tearfulness and loss of interest or pleasure in daily activities. It is also traditionally used for anxiety and nervous restlessness.
• In traditional western herbal medicine, herbs used to relieve fluid retention include dandelion leaf, cleavers and uva-ursi.
• Chromium assists in the uptake of glucose into cells and supports blood sugar balance.