Lots of people feel low or irritable in the days before their period. This is part of premenstrual syndrome (PMS) and it's very common. For a smaller number of people, these feelings are severe enough to get in the way of daily life. This is called premenstrual dysphoric disorder, or PMDD.
Why do I experience mood changes?
After ovulation, the hormones oestrogen and progesterone rise and then fall quickly in the days before your period. These hormones affect chemicals in the brain that help control mood. People with PMDD usually have normal hormone levels, but their brain seems to react more strongly to the normal rise and fall.
What PMDD looks like
With PMDD, symptoms start in the week or two before your period, ease within a few days of your period starting, and are mostly gone in the week after. They can include:
feeling very sad or hopeless
feeling anxious or tense
sudden mood swings or crying
feeling angry or getting into more arguments
losing interest in things you usually enjoy
finding it hard to concentrate
feeling very tired or sleeping a lot more or less
About 3 in every 100 people who have periods have PMDD.
Would tracking help?
PMDD is diagnosed by recording your symptoms every day for at least two cycles. This shows whether the symptoms really follow your cycle. Our cycle tracker has a row for mood, which is a good place to start.
If you feel low most of the month and it gets worse before your period, that's a different pattern. It's still worth telling a doctor about.
What helps
Regular exercise and good sleep can help with milder PMS. For PMDD, a doctor can talk you through treatments that work, including talking therapy and medicines. You don't have to just get through it each month.
Please read this part
PMDD has been strongly linked with thoughts of suicide. If you ever have thoughts of hurting yourself or ending your life, tell someone you trust and contact a doctor or a helpline straight away. You don't have to wait for the feeling to pass.
When to see a doctor
your mood before your period is affecting your studies or your relationships
you feel hopeless or very anxious every month
you're losing interest in things you usually enjoy
you've had any thoughts of hurting yourself