Premenstrual syndrome (PMS)
Premenstrual syndrome (PMS) (also called PMT or premenstrual tension) is a collection of physical, psychological, and emotional symptoms related to a woman's menstrual cycle. While most women of child-bearing age (up to 85%) report having experienced physical symptoms related to normal ovulatory function, such as bloating or breast tenderness, medical definitions of PMS are limited to a consistent pattern of emotional and physical symptoms occurring only during the luteal phase of the menstrual cycle that are of "sufficient severity to interfere with some aspects of life". These symptoms are usually predictable and occur regularly during the ten days prior to menses. Generally, symptoms may vanish either shortly before or after the start of menstrual flow.
Only a small percentage of women (2 to 5%) have significant premenstrual symptoms that are separate from the normal discomfort associated with menstruation in healthy women.
Culturally, the abbreviation PMS is widely understood in English-speaking countries to refer to difficulties associated with menses, and the abbreviation is used frequently even in casual and colloquial settings, without regard to medical rigor. In these contexts, the syndrome is rarely referred to without abbreviation, and the connotations of the reference are frequently more broad than the clinical definition.
More than 200 different symptoms have been associated with PMS, but the three most prominent symptoms are irritability, tension, and dysphoria (unhappiness). Common emotional and non-specific symptoms include stress, anxiety, difficulty in falling asleep (insomnia), headache, fatigue, mood swings, increased emotional sensitivity, and changes in libido. Most formal definitions require the presence of emotional symptoms as the chief complaint; the presence of exclusively physical symptoms associated with the menstrual cycle, such as bloating, abdominal cramps, constipation, swelling or tenderness in the breasts, cyclic acne, and joint or muscle pain, is not considered PMS.
The exact symptoms and their intensity vary from woman to woman and even from cycle to cycle. Most women with premenstrual syndrome experience only a few of the possible symptoms, in a relatively predictable pattern. Under typical definitions, symptoms must be present at some point during the ten days immediately before the onset of menses, and must not be present for at least one week between the onset of menses and ovulation. Although the intensity of symptoms may vary somewhat, most definitions require that the woman's unique constellation of symptoms be present in multiple, consecutive cycles.
- High caffeine intake
- Stress may precipitate condition
- Increasing age
- History of depression
- Tobacco use
- Family history
- Dietary factors (Low levels of certain vitamins and minerals, particularly magnesium, manganese, and vitamin E)
Family history is often a good predictor of the probability of premenstrual syndrome; studies have found that the concordance rate is two times higher among identical twins compared with fraternal twins. Although the presence of premenstrual syndrome is high among women with affective disorders such as depression and bipolar disorder, a causal relationship has not been established.
Vitamin B can also assist with unstable emotions.
There is no laboratory test or unique physical findings to verify the diagnosis of PMS. The three key features are:
- The woman's chief complaint is one or more of the emotional symptoms associated with PMS (most typically irritability, tension, and/or unhappiness).
- Symptoms appear predictably during the luteal (premenstrual) phase, reduce or disappear predictably shortly before or during menstruation, and remain absent during the follicular (pre-ovulatory) phase of the menstrual cycle.
- The symptoms must be severe enough to disrupt or interfere with the woman's everyday life.
To establish a pattern, a woman's physician may ask her to keep a prospective record of her symptoms on a calendar for at least two menstrual cycles. This will help to establish if the symptoms are, indeed, limited to the premenstrual time and are predictably recurring. A number of standardized instruments have been developed to describe PMS, including the Calendar of Premenstrual syndrome Experiences (COPE), the Prospective Record of the Impact and Severity of Menstruation (PRISM), and the Visual Analogue Scales (VAS).
In addition, other conditions that may better explain symptoms must be excluded. A number of medical conditions are subject to exacerbation at menstruation, a process called menstrual magnification. These conditions may lead the patient to believe that she has PMS, when the underlying disorder may be some other problem, such as anemia, hypothyroidism, eating disorders and substance abuse. A key feature is that these conditions may also be present outside of the luteal phase. Conditions that can be magnified perimenstrually include depression or other affective disorders, migraine, seizure disorders, fatigue, irritable bowel syndrome, asthma, and allergies. Also, problems with other aspects of the female reproductive system must be excluded, including dysmenorrhea (pain during menses, rather than before it), endometriosis, perimenopause, and adverse effects produced by oral contraceptive pills.
Although there is no universal agreement about what qualifies as PMS, two definitions are commonly used in research programs:
- The National Institute of Mental Health research compares the intensity of symptoms from cycle days 5 to 10 to the six-day interval before the onset of menses. To qualify as PMS, symptom intensity must increase at least 30% in the six days before menstruation. Additionally, this pattern must be documented for at least two consecutive cycles.
- The definition formulated at the University of California at San Diego requires both affective (emotional) and somatic (physical) symptoms during the five days before menses in each of three consecutive cycles, and must not be present during the pre-ovulatory part of the cycle (days 4 through 13). For this definition, affective symptoms include symptoms like depression, angry outbursts, irritability, anxiety, confusion, and social withdrawal. Somatic symptoms include symptoms like breast tenderness, abdominal bloating, headache, and swelling of hands and feet.
The exact causes of PMS are not fully understood. While PMS is linked to the luteal phase, measurements of sex hormone levels are within normal levels. PMS tends to be more common among twins, suggesting the possibility of some genetic component. Current thinking suspects that central-nervous-system neurotransmitter interactions with sex hormones are affected. It is thought to be linked to activity of serotonin (a neurotransmitter) in the brain.
Genetic factors also seem to play a role, as the concordance rate is two times higher in monozygotic twins than in dizygotic twins. Preliminary studies suggest that up to 40% of women with symptoms of PMS have a significant decline in their circulating serum levels of beta-endorphin. Beta endorphin is a naturally occurring opioid neurotransmitter which has an affinity for the same receptor that is accessed by heroin and other opiates. Some researchers have noted similarities in symptom presentation between PMS symptoms and opiate withdrawal symptoms.
A variety of evolutionary rationales for the syndrome have been offered, including that it is an epiphenomenon due to the selective advantage accruing to other phases of the hormonal cycle, that it leads to "intensification of male ardour during the next onset of fertility", and that it prompts females to reject infertile males (who cause PMS due to not impregnating the female). "… an infertile male/potentially fertile female partnership would tend to break down, thus allowing a new pair-bond to be formed. The greater the degree of premenstrual hostility of the female, the sooner a fertile mating could ensue." Any theory would have to account for the persistence of PMS over substantial evolutionary time, as it appears to afflict baboons as well.
Many treatments have been suggested for PMS, including diet or lifestyle changes, and other supportive means. Medical interventions are primarily concerned with hormonal intervention and use of selective serotonin reuptake inhibitors (SSRIs).
- Supportive therapy includes evaluation, reassurance, and informational counseling, and is an important part of therapy in an attempt to help the patient regain control over her life. In addition, aerobic exercise has been found in some studies to be helpful. Some PMS symptoms may be relieved by leading a healthy lifestyle: Reduction of caffeine, sugar, and sodium intake and increase of fiber, and adequate rest and sleep.
- Dietary intervention studies indicate that calcium supplementation (1200 mg/d) may be useful. Also vitamin E (400 IU/d) has shown some effectiveness. A number of other treatments have been suggested, although research on these treatments is inconclusive so far: Vitamin B6, magnesium, manganese and tryptophan.
- SSRIs can be used to treat severe PMS. These drugs can also be given intermittently, that is when symptoms are expected to occur. Although intermittent therapy might be more acceptable to some women, this might be less effective than continuous regimens.
- Hormonal intervention may take many forms:
- Hormonal contraception is commonly used; common forms include the combined oral contraceptive pill and the contraceptive patch. This class of medication may cause PMS-related symptoms in some women, and may reduce physical symptoms in other women. They do not relieve emotional symptoms.
- Progesterone support has been used for many years but evidence of its efficacy is inadequate.
- Gonadotropin-releasing hormone agonists can be useful in severe forms of PMS but have their own set of significant potential side effects.
- Diuretics have been used to handle water retention. Spironolactone has been shown in some studies to be useful.
- Non-steroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen) have been used to treat pain.
- Evening primrose oil, which contains gamma-Linolenic acid (GLA), has been advocated but lacks scientific support.
- Clonidine has been reported to successfully treat a significant number of women whose PMS symptoms coincide with a steep decline in serum beta-endorphin on a monthly basis.
- Chasteberry has been used by women for thousands of years to ease symptoms related to menstrual problems. It is believed some of the compounds found within Chasteberry work on the pituitary gland to balance hormone levels.
- DL phenylalanine can reduce or prevent symptoms of PMS in some women. It is only effective when the PMS is associated with an abrupt decline in circulating serum beta-endorphin levels.
- Recent evidence suggests that daily treatment with St. Johns wort (Hypericum perforatum) may improve the most common physical and behavioural symptoms associated with PMS.
PMS is generally a stable diagnosis, with susceptible women experiencing the same symptoms at the same intensity near the end of each cycle for years.
Treatment for specific symptoms is usually effective at controlling the symptoms. Even without treatment, symptoms tend to decrease in perimenopausal women, and disappear at menopause.
Women who have PMS have an increased risk for clinical depression.
The number of women who experience PMS depends entirely on the stringency of the definition of PMS. While 80% of menstruating women have experienced at least one symptom that could be attributed to PMS, estimates of prevalence range from as low as 3% to as high as 30%.
Mood symptoms such as emotional lability are both more consistent and more disabling than somatic symptoms such as bloating. A woman who experiences mood symptoms is likely to experience these symptoms consistently and predictably, whereas physical symptoms may come and go. Most women find that physical symptoms related to PMS are less disruptive than emotional symptoms