Hormones and feelings · For ages 13–17
Why does my mood change so much before my period?
Some people notice clear changes in mood, energy or physical symptoms before their period. If these changes follow the menstrual cycle, they may be PMS.
What happens?
PMS can affect the body and emotions
PMS stands for premenstrual syndrome. It describes symptoms that occur before a period and get better when bleeding starts or shortly afterwards.
Some people become more irritable, sad, sensitive or anxious. Others have tender breasts, bloating, headaches, a bigger appetite or less energy.
If emotional symptoms become very intense and have a major effect on school, relationships or everyday life, it is important to seek help to assess whether there is more going on than ordinary changes across the cycle.
Learn more
Which describes what you have noticed?
Choose the option that fits best to see guidance on what you can do next.
Irritability can be part of PMS if it comes before menstruation and improves afterwards.
Notice whether the irritability appears before bleeding and eases afterwards. Record the days you feel well too. Sleep, stress and relationships can affect mood in addition to your cycle.
Try planning breaks and explaining what you need. If this repeatedly causes problems at school or home, you can get help exploring the pattern and possible solutions.
Strong emotional changes before your period deserve to be taken seriously, especially if they affect daily life. Tracking the pattern and speaking with a doctor may help.
Severe emotional symptoms before a period may be related to PMS or PMDD, but should also be assessed alongside how you feel during the rest of the month. A cyclical pattern is useful information, rather than a diagnosis in itself.
Ask for help now. Daily tracking can support an assessment, but you should not wait several cycles if the situation is serious.
Try recording your mood and the first day of each period over a few cycles. It may help you identify a pattern.
Make brief notes about mood and the first day of bleeding, including the days you feel well. Ask yourself whether symptoms ease between periods or remain throughout the month.
You can discuss either pattern with a healthcare professional. The goal is to find suitable support, rather than explain every feeling with hormones. You do not need proof of a link before booking an appointment.
What can you do now?
If the changes affect school, sleep, relationships or how you function, you can speak with a doctor or school nurse.
You can write down how you feel each day for two cycles so that you and the doctor can look for a pattern. You can ask for help now; you do not have to wait until you have finished tracking. If you feel unwell throughout the month, it is important to get help with that too.
Find the words you need
Create a short message you can say, show or send to someone you trust, a school nurse or a doctor.
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