Dysmenorrhoea is estimated to occur in 20% to 90% of women of reproductive age. It is the most common menstrual disorder. Typically it starts within a year of the first menstrual period. When there is no underlying cause often the pain improves with age or following having a child. Symptoms often co-occurring with menstrual pain include nausea and vomiting, diarrhea or constipation, headache, dizziness, disorientation, hypersensitivity to sound, light, smell and touch, fainting, and fatigue. Non-steroidal anti-inflammatory drugs are effective in relieving the pain of primary dysmenorrhoea.