Premenstrual syndrome (PMS) is a group of physical, emotional, and behavioral symptoms that occur during the days or weeks before a menstrual period and usually improve after the period begins. Common symptoms include mood changes, irritability, breast tenderness, bloating, headaches, fatigue, food cravings, and changes in sleep or appetite.
PMS is linked to the normal hormonal changes that occur during the menstrual cycle, but hormones are not the whole explanation. Some people appear to be more sensitive to these hormonal shifts than others. The severity and combination of symptoms can also vary from one cycle to the next.
What causes PMS?
The exact cause of PMS is not completely understood. The symptoms are closely associated with the hormonal changes that occur after ovulation, particularly changes in estrogen and progesterone during the second half of the menstrual cycle.
After ovulation, progesterone rises and estrogen levels also change. If pregnancy does not occur, these hormones eventually fall, triggering menstruation. In people who experience PMS, the nervous system and other tissues may respond differently to these normal hormonal fluctuations.
Brain chemicals may also contribute. Changes in ovarian hormones can influence neurotransmitters such as serotonin, which helps regulate mood, sleep, appetite, and other functions. This may help explain why PMS can involve both physical symptoms and changes in mood or behavior.
PMS is therefore not simply a problem caused by having unusually high or low hormone levels. Two people can have similar hormonal changes but experience very different symptoms.
What are the symptoms of PMS?
PMS can affect several parts of the body and can influence mood, behavior, and daily functioning. Symptoms generally appear during the latter part of the menstrual cycle and improve after menstruation begins.
Physical symptoms may include:
- Breast tenderness or swelling
- Bloating or a feeling of fullness
- Headaches
- Fatigue
- Abdominal discomfort or cramping
- Muscle or joint aches
- Changes in appetite
- Food cravings
- Acne flare-ups
- Constipation or diarrhea
- Changes in sleep
Emotional and behavioral symptoms can include irritability, mood swings, sadness, anxiety, tension, difficulty concentrating, and reduced interest in usual activities.
Not everyone experiences the same combination of symptoms. One person may mainly have breast tenderness and bloating, while another may experience prominent mood changes, fatigue, and food cravings.
When do PMS symptoms occur?
The timing of symptoms is one of the most important features of PMS.
Symptoms typically develop after ovulation, during the second half of the menstrual cycle. They often become more noticeable as the next period approaches and then improve shortly after menstruation begins.
This repeating pattern helps distinguish PMS from symptoms caused by conditions that are present throughout the month. If symptoms occur at other times in the cycle as well, or do not improve after menstruation begins, another condition may need to be considered.
Keeping track of symptoms over several menstrual cycles can make this pattern easier to recognize.
Why does PMS affect mood?
PMS can cause irritability, anxiety, sadness, emotional sensitivity, or sudden changes in mood. These symptoms are thought to result partly from how changes in ovarian hormones affect brain signaling.
Serotonin is one of the important systems involved. Because serotonin influences mood, sleep, appetite, and other functions, changes in its activity may contribute to several PMS symptoms at once.
Mood symptoms do not mean that PMS is simply psychological. The symptoms are associated with biological changes during the menstrual cycle, although stress, sleep, and other factors can influence how strongly they are experienced.
What can make PMS symptoms worse?
PMS symptoms can be influenced by factors that affect overall physical and emotional well-being. Poor sleep, high stress, and limited physical activity may make symptoms more difficult to manage.
Diet can also affect how some people feel during this part of the cycle. Large amounts of salty foods may contribute to fluid retention and bloating, while excessive caffeine can worsen sleep problems or make some people feel more restless or anxious.
These factors do not necessarily cause PMS, but addressing them can reduce the burden of symptoms for some people.
How is PMS managed?
Treatment depends on which symptoms are most troublesome and how much they interfere with daily life. Mild PMS often improves with lifestyle measures, while more disruptive symptoms may require medication or other treatment.
Regular physical activity can help some people manage PMS symptoms, particularly mood changes and fatigue. Adequate sleep and a consistent sleep schedule are also useful because sleep disruption can compound fatigue, irritability, and difficulty concentrating.
Eating a balanced diet and limiting foods that clearly worsen individual symptoms can also help. Some people find it useful to reduce excessive salt, caffeine, or alcohol, particularly when these contribute to bloating, breast discomfort, sleep problems, or mood changes.
For pain, headaches, or cramps, over-the-counter pain relievers such as ibuprofen or naproxen may help when they are safe for the individual to use. Acetaminophen can also relieve some types of pain. Medication choice should take into account other medical conditions and medicines being used.
Hormonal birth control can help some people by suppressing or altering the hormonal fluctuations associated with the menstrual cycle. However, its effects on PMS vary, and a particular method may improve some symptoms while having less effect on others.
For significant mood-related symptoms, clinicians may sometimes use antidepressant medications that affect serotonin signaling, particularly selective serotonin reuptake inhibitors (SSRIs). These medications can be effective for more severe premenstrual symptoms and may be used continuously or during part of the menstrual cycle depending on the situation.
How can you tell whether symptoms are really PMS?
The recurring pattern is more informative than any single symptom.
A useful approach is to record symptoms each day for at least a few menstrual cycles. The record can include mood, physical symptoms, sleep, appetite, and the timing of menstruation. This can show whether symptoms consistently appear before the period and improve afterward.
Tracking also helps distinguish PMS from symptoms that are present throughout the menstrual cycle. It gives a healthcare professional more useful information when evaluating persistent or severe symptoms.
PMS vs. PMDD
PMS and premenstrual dysphoric disorder (PMDD) are related but are not the same condition.
PMDD is a more severe disorder in which premenstrual symptoms, particularly emotional and mood-related symptoms, are intense enough to cause substantial distress or interfere significantly with work, relationships, or daily activities. Irritability, depression, anxiety, or marked mood changes can be prominent.
The distinction is based largely on the severity, pattern, and impact of symptoms rather than simply having a particular symptom. Someone with occasional mild irritability before a period does not necessarily have PMDD.
Persistent depression or anxiety outside the premenstrual period can also indicate another condition rather than PMS alone.
When should you see a healthcare professional?
It is worth discussing PMS with a healthcare professional when symptoms regularly interfere with work, school, relationships, sleep, or normal activities, or when self-care measures are not enough.
Severe mood symptoms deserve particular attention. Feeling persistently depressed, experiencing extreme anxiety, or having thoughts of self-harm should not be dismissed as ordinary PMS. These symptoms require prompt professional evaluation, especially if they occur outside the premenstrual part of the cycle.
A healthcare professional can also look for other conditions that can resemble PMS, including depression, anxiety disorders, thyroid problems, migraine, and other menstrual or hormonal conditions.
PMS is a recurring response to the hormonal changes of the menstrual cycle, but its symptoms are real and can range from mild inconvenience to substantial disruption. Recognizing the timing and pattern of symptoms is an important first step toward finding an effective way to manage them.
