The list of potential signs and symptoms for premenstrual syndrome is long, but most women only experience a few of these problems.

Emotional and behavioral signs and symptoms

• Tension or anxiety
• Depressed mood
• Crying spells
• Mood swings and irritability or anger
• Appetite changes and food cravings
• Trouble falling asleep (insomnia)
• Social withdrawal
• Poor concentration
• Change in libido

Physical signs and symptoms

• Joint or muscle pain
• Headache
• Fatigue
• Weight gain related to fluid retention
• Abdominal bloating
• Breast tenderness
• Acne flare-ups
• Constipation or diarrhea
• Alcohol intolerance

For some, the physical pain and emotional stress are severe enough to affect their daily lives. Regardless of symptom severity, the signs and symptoms generally disappear within four days of the start of the menstrual period for most women.

But a small number of women with premenstrual syndrome have disabling symptoms every month. This form of PMS is called premenstrual dysphoric disorder (PMDD).

PMDD signs and symptoms include depression, mood swings, anger, anxiety, feeling overwhelmed, difficulty concentrating, irritability and tension.

Exactly what causes premenstrual syndrome is unknown, but several factors may contribute to the condition:

• Cyclic changes in hormones. Signs and symptoms of premenstrual syndrome change with hormonal fluctuations and disappear with pregnancy and menopause.
• Chemical changes in the brain. Fluctuations of serotonin, a brain chemical (neurotransmitter) that's thought to play a crucial role in mood states, could trigger PMS symptoms. Insufficient amounts of serotonin may contribute to premenstrual depression, as well as to fatigue, food cravings and sleep problems.
• Depression. Some women with severe premenstrual syndrome have undiagnosed depression, though depression alone does not cause all of the symptoms.