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The menstrual cycle is controlled by female hormones that generally cause a regular bleed, often called a 'period'.

In these pages you will learn all about the menstrual cycle, periods, heavy bleeding, regular and irregular bleeding, period pain, premenstrual syndrome (PMS), breast pain and sex when you have your period.

There is also information on what causes changes to your menstrual cycle and period, and what treatments are available if you need help with your period.

This section of the website is currently being reviewed. It will be updated in early 2024. Please visit our fact sheets or resources for more information on periods.

This con­tent has been reviewed by a group of med­ical sub­ject mat­ter experts, in accor­dance with Jean Hailes pol­i­cy.