After you've been able to document the cyclical nature of your symptoms and their severity, you and your doctor can develop a treatment plan. Your doctor may first recommend simple lifestyle changes, since PMS often responds remarkably well to modifications in eating habits, stress management, and increased amounts of sleep or exercise.

Caffeine is a major culprit of PMS symptoms. Found in a variety of substances—coffee, tea, soft drinks, chocolate and some over-the-counter medications—caffeine is a stimulant that is often consumed precisely for the "lift" it provides. Nevertheless, caffeine can exaggerate PMS-related problems such as anxiety, insomnia, nervousness, and irritability, and it can interfere with carbohydrate metabolism by depleting your body of B vitamins. Reducing your caffeine intake is a smart move to counteract PMS symptoms and can provide almost instant relief. In fact, some doctors routinely advise eliminating caffeine from the diet before every menstrual period as a first step in coping with PMS.

Many women with PMS gain several pounds during the two weeks preceding their period, much of this in fluid weight. Avoiding salty foods can dramatically reduce bloating and water buildup, resulting in less breast and abdominal tenderness and less swelling in the hands and feet. Since brain cells also have a tendency to retain fluid, you may find that a salt-free diet eliminates or curbs headaches and allows you to concentrate better.

Sugar can also play havoc on your body, especially in the days preceding your period. Eating sugary foods often initiates a vicious cycle of additional sugar cravings, as an increase in your body's need for B-complex vitamins prompts even more craving for sugar-laden simple carbohydrates. Although a link between PMS and difficulties in metabolizing sugar has not been proven, consuming sweets can put your body on a roller coaster between feeling weak and feeling high strung and jittery—your body's response to low sugar levels at one extreme, and elevated sugar levels at the other.

Nicotine, a brain stimulant, can magnify PMS symptoms much like caffeine, so reducing or eliminating smoking should be part of any treatment program. Alcohol can also intensify symptoms because it depletes the body of B vitamins, disrupts the metabolism of carbohydrates, and affects the liver's ability to process hormones.

Some foods may genuinely relieve PMS symptoms. Complex carbohydrates such as whole grains, beans, fresh fruits, and vegetables help to maintain your body's essential vitamins and minerals. Eating a low-fat diet based on grains and vegetables while reducing your intake of red meat—especially during the two weeks prior to the beginning of your period—may help to control your PMS symptoms. And at least one study has suggested that taking a supplementary 1,200 milligrams of calcium per day reduces many PMS symptoms, including irritability, water retention, food cravings, and pain.

Many women also find that exercise produces positive benefits in moderating PMS symptoms, while improving their general health. Consider a monthly workout plan that rotates activities designed to strengthen your muscles, reduce fat, and relieve tension. Vigorous exercise—running, biking, swimming, aerobics, racquet sports and the like—has been shown to elevate your mood and improve alertness, while calisthenics and body-building tone muscles and improve strength. Contrary to popular belief, exercise helps to control—not increase—your appetite.

With your doctor's approval, try a program that mixes more vigorous cardiovascular exercises during the early days of your menstrual cycle with stretching, flexibility exercises, and less vigorous cardiovascular work such as walking on the days when you're most prone to PMS symptoms. This regimen can increase your heart-lung capacity and improve your overall physical condition while reducing the strain on your breasts, thighs, and abdomen during the latter phase of your cycle.

PMS is also associated with disruptions in a woman's normal sleep patterns. Women with moderate to severe PMS symptoms are more likely to complain of insomnia and are known to spend less time in deep sleep than those who are symptom-free. Reducing caffeine intake can help. You may also benefit from short naps on certain days. In any event, try to get at least eight hours of uninterrupted sleep each night, especially during the latter half of your cycle.

You may also benefit from some stress management techniques. Unlike diet, exercise, and sleep, outside stress is the one factor of daily life that no one can control. How you approach and handle stress, however, can have a tremendous impact on your behavior and mood.

The causes of stress can be physical, such as chronic or episodic illness or injury; psychological, such as fears, anxieties, or frustrations; and social, such as crying children, rush-hour traffic, and even holiday preparations. These everyday aggravations are particularly annoying during the days you're experiencing PMS symptoms.

A stress management class can help you channel the tension caused by stress so you are less likely to lose control, a common complaint of women with PMS. Whether they emphasize breathing exercises, visualization, biofeedback, or other stress management techniques, a common theme is to help you maintain a positive attitude and develop realistic expectations.

How much improvement you can expect from these remedies—and how quickly—depends largely on your commitment to them and your willingness to change your habits. You may notice dramatic improvements almost immediately, or gradual improvement over several menstrual cycles. As you continue to record your symptoms, you may observe that more sleep or a brisk walk helps during certain premenstrual days, while modifying your diet helps during others. The bottom line is to focus on continual improvement rather than dwell on the symptoms.

Even though you can make many of these lifestyle and dietary changes without seeing a physician, it's better to enlist your doctor's expertise in developing a program tailored to your particular PMS symptoms and other health factors. Since no single treatment is uniformly effective for PMS, you can benefit from your physician's experience with other women who are successfully managing their condition.

PMS or PMDD? PMS has been linked to serious psychological problems in a small group of women. In Great Britain, women have been acquitted of various crimes on the grounds that the PMS from which they were suffering at the time of their action caused a temporary psychiatric disturbance. Though PMS is not recognized as a valid legal defense in the United States, the American Psychiatric Association (APA) recognized the possible psychiatric implications of PMS when it classified the related Premenstrual Dysphoric Disorder (PMDD) as a "depressive disorder not otherwise specified," and included it in the appendix of the APA's Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV. PMDD, which is thought to affect fewer than 5 percent of menstruating women, is described by the APA as a pattern of severe, recurrent symptoms of depression and other negative moods that occur during the last week of the menstrual cycle and markedly interfere with daily living. While PMDD is not an official diagnostic category, the APA hopes its inclusion in DSM-IV will encourage further psychiatric research into the condition. (See "Spelling out PMDD.")