PMS 101

Symptoms of PMS such as headaches and fatigue can be debilitating and interfere with everyday life.

Every month like clockwork, some women come down with a strange collection of symptoms. They may become irritable, snapping at their family and friends without the slightest provocation. They may forget where they put their car keys and have trouble paying attention during meetings at work. They may crave chocolate or find themselves sneaking a few pieces of pizza after their children have gone to bed. Or they may suddenly hate the way they look because they feel bloated and their hair looks oily and lifeless.

We are quick to give these symptoms a label: premenstrual syndrome, or PMS. But what is PMS? Some people dismiss it as "that time of the month" -- an excuse that women give in order to eat tons of chocolate and get away with acting a bit cranky.


But doctors recognize PMS as a real medical condition, with real physical and psychological symptoms. For many women, the symptoms are debilitating enough to interfere with their lives.

What is PMS?

Premenstrual Syndrome (PMS) is a set of hormonal changes that trigger a wide range of physical and emotional symptoms in women. These symptoms can range from anger and irritability, to abdominal cramping and breast tenderness, to food cravings. PMS generally occurs between 7 to 14 days before menstruation (a woman's monthly bleeding, or "period") and then stops once menstruation begins. It can only occur during a woman's childbearing years -- after menopause, it stops.

Up to 40 percent of menstruating women experience symptoms of PMS [ref]. In most of these women, PMS is nothing more than an annoyance. But in about 5 percent of women, the symptoms are debilitating enough to interfere with daily life.

In this article, we'll discover how doctors identify PMS, learn the underlying causes of this ailment and find out how women who suffer from it can find relief. 




PMS Symptoms

There are more than 150 different symptoms associated with PMS, so it is often difficult to diagnose. Although there is no real test for PMS, doctors will do tests to rule out other conditions that cause similar symptoms. When a woman's symptoms coincide with her menstrual cycle, and she tests negative for other conditions, PMS is usually determined to be the cause of her symptoms. Keeping a monthly diary of symptoms is helpful to confirm the diagnosis.

Some conditions to rule out when diagnosing PMS:


  • Anemia
  • Eating disorders
  • Diabetes
  • Alcohol abuse
  • Hypothyroidism
  • Oral contraceptive side effects
  • Perimenopause
  • Dysmenorrhea
  • Chronic fatigue syndrome
  • Endometriosis
  • Autoimmune disorders

There are more than 150 physical and psychological symptoms associated with PMS. These symptoms can vary from mild to severe, from person to person and from cycle to cycle.

General PMS symptoms include:

Psychological symptoms

  • Mood changes (e.g., crying for no reason, depression, anxiety, anger, sadness or irritability)
  • Changes in mental functioning (inability to concentrate or remember)
  • Changes in sex drive (increased or decreased libido)

Physical symptoms

  • Upset stomach, diarrhea or constipation
  • Fatigue
  • Difficulty sleeping
  • Headache
  • Fluid retention/bloating
  • Acne
  • Breast tenderness
  • Joint or muscle pain
  • Cramping
  • Food cravings (especially for carbohydrates, chocolate and other sweets)
  • Weight gain

In the next section, we'll look at some of the factors that may contribute to PMS.


What Causes PMS?

Scientists don't know exactly why women get PMS or why some women experience it more severely than others. But they believe that it stems from a combination of hormonal changes, genetics, nutrition and psychological factors.

The Menstrual Cycle

Hormones are one of the most studied aspects of PMS's origins. PMS occurs near the end of a woman's menstrual cycle, within seven to 14 days before menstruation. During this cycle, which takes about 28 days, an egg matures and is released from the ovaries for possible fertilization. The hormones estrogen and progesterone play a big part in the menstrual cycle.


At around five days into the menstrual cycle, the ovaries release the female hormone estrogen. This hormone helps thicken the uterus, which will nourish an embryo if conception occurs. At around 14 days into the cycle, the egg is released in a process called ovulation. After ovulation, the last (luteal) phase of the menstrual cycle begins, and PMS symptoms tend to emerge. During this phase, the ovaries increase production of estrogen and begin producing progesterone to prepare the uterus for a possible pregnancy. If the egg is not fertilized, production of estrogen and progesterone drops. This hormonal drop causes the lining of the uterus to die and slough off, leading to menstruation. Once menstruation starts, PMS symptoms stop with a day or two. (See How Menstruation Works to learn more about the menstrual cycle.)

Researchers believe that the hormones estrogen and progesterone interact with certain brain chemicals, called neurotransmitters, and that this interaction can affect mood and contribute to other PMS symptoms. Let's take a look at some of the specific neurotransmitters researchers believe are involved in PMS.

Hormones and Neurotransmitters

Researchers believe that the following neurotransmitters are affected by estrogen and/or progesterone during the menstrual cycle and may lead to some of the symptoms of PMS:

  • Serotonin regulates mood and sleep patterns and creates feelings of well-being. Reduced levels of estrogen during the luteal phase may be linked to a drop in serotonin. Lower serotonin levels are associated with depression, irritability, anger and carbohydrate cravings, all of which are symptoms of PMS.
  • Gamma-aminobutyric acid (GABA) is a neurotransmitter associated with anxiety and depression. Progesterone may increase the activity of this neurotransmitter.
  • Endorphins increase feelings of pleasure and reduce the intensity of pain. Both estrogen and progesterone may affect endorphin levels.
  • Norepinephrine and epinephrine are neurotransmitters involved in the body's stress response. Estrogen may affect the levels of these neurotransmitters, which can influence blood pressure and heart rate as well as mood.

Whether symptoms are influenced by increased or decreased levels of estrogen and progesterone is a matter of some debate. Studies routinely produce conflicting results. Some researchers believe that the key to PMS symptoms lies in the balance between these two hormones during the menstrual cycle.


Diet and PMS

We don't know exactly how diet impacts PMS. But some research has shown that increasing complex carbohydrates before menstruation helps increase the levels of the neurotransmitter serotonin, a deficiency of which has been linked to PMS-related depression. Although complex carbohydrates (such as those found in whole grains and vegetables) are good to eat during PMS, simple carbohydrates (such as those found in sugary snacks and white bread) can actually increase water retention, irritability and other PMS symptoms.

Experts also recommend that menstruating women take vitamins, especially a daily multivitamin containing folic acid (which is essential for the growth of the fetus should conception occur) and a calcium supplement with vitamin D (which helps bones stay strong and may also help alleviate PMS symptoms). Some researchers think Vitamin B6 may ease symptoms, particularly depression, but its effectiveness has not been clinically proven, and very high doses (500 mg to 2,000 mg daily) can cause nerve damage.


Dieticians sometimes recommend that women who are experiencing PMS eat several small meals throughout the day rather than three big meals. Eating a lot of food at once can cause blood sugar to swing up and down, which some people believe might exacerbate PMS symptoms.

Experts say that certain foods should be avoided:

  • Caffeine, because it can increase irritability, nervousness and insomnia
  • Alcohol, because it can act as a depressant
  • Salt, because it can increase water retention and bloating

Women should also avoid nicotine because, in addition to its other health risks, it can affect PMS symptoms much like caffeine.

A 2005 study found that women who ate a diet rich in vitamin D and calcium had less of a risk of developing PMS than women who didn't eat these nutrients. To see a benefit, the women in the study had to eat at least 1,200 milligrams of calcium and 400 IU of vitamin D each day. Researchers don't know exactly why vitamin D and calcium warded off PMS symptoms, but they say it may have something to do with calcium's effect on the hormone estrogen during the menstrual cycle.



Treatments for PMS

In addition to dietary changes, milder PMS symptoms can be alleviated by simple lifestyle changes, primarily through exercise and reducing stress.

Exercise During a workout, levels of chemicals called beta-endorphins rise. These chemicals positively impact mood and behavior. Experts say that exercising at least three times a week can reduce anger and depression and fight stress during PMS.


Stress Reduction Although stress doesn't cause PMS, it can worsen its symptoms. Relaxation techniques such as meditation and yoga are often effective in relieving stress.

Medications When diet, exercise and stress reduction aren't enough to alleviate symptoms, medications may be needed. Over-the-counter medicines, such as those containing acetaminophen (Tylenol) and ibuprofen (Motrin), can relieve cramping and other minor aches and pains. Some medications are marketed specifically to women experiencing PMS symptoms. These medications, which include Midol and Pamprin, typically include a combination of aspirin or acetaminophen for pain plus diuretics. Diuretics prevent water retention to relieve bloating. For women with PMDD (see below), antidepressant drugs such as sertraline hydrochloride (Zoloft) and fluoxetine (Prozac, Sarafem) can alleviate depression. In severe cases, birth control pills can be used to stop ovulation completely.

For more information on PMS and related topics, check out the links on the next page.


Lots More Information

Related Articles

More Great Links

  • Hale, Ellen. "Relieving PMS."
  • "Hormones Trigger PMS - But Susceptibility Still a Mystery." National Institutes of Health Press Release, January 21, 1998.
  • "Menstruation and the Menstrual Cycle."
  • "Medical Treatment of PMS Premenstrual Syndrome."
  • The National Women's Health Information Center. Premenstrual Syndrome.
  • "PMS and Adrenal Stress Hormones" Great Smokies Diagnostic Lab.
  • "PMS and Female Sex Hormones." Great Smokies Diagnostic Labs.
  • "PMS: Sorting Fact from Fiction."
  • Premenstrual Syndrome.
  • U.S. Food and Drug Administration, Updates, September-October 2000.
  • Watson, Stephanie and Miller, Kelli. The Endocrine System. Westport, CT: Greenwood Publishing Group, Inc, 2004.
  • "What are the Lifestyle Measures for Managing Premenstrual Syndrome?"
  • "What Causes Premenstrual Syndrome?"