---
title: Does fluid around the brain change before your period? | Niyora
description: Yes, fluid around the brain increased in nearly all women before menstruation. However, this happened because the brain itself became slightly smaller, not be
url: https://niyora.com/research/papers/is-cranial-csf-volume-under-hormonal-influence-an-mr-study-1988/
---

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- Does fluid around the brain change before your period?

Study, 1988

# Does fluid around the brain change before your period?

Yes, fluid around the brain increased in nearly all women before menstruation. However, this happened because the brain itself became slightly smaller, not because the brain was swelling.

 Early or limited evidence

20 women with regular menstrual cycles, plus 10 postmenopausal women and 10 men as comparison groups

## What they did

Researchers used MRI scans to measure fluid around the brain and inside the brain's ventricles. They scanned 20 women with regular cycles at two times: in the middle of the cycle and before menstruation. For comparison, they also scanned 10 postmenopausal women and 10 men twice, two weeks apart.

## What they found

In 19 of the 20 women, fluid around the brain increased before menstruation. The average increase was 11.5 ml. Women taking birth control pills had similar changes to women not taking them. Fluid did not change in the men or postmenopausal women. The increase in fluid was because brain volume decreased, not because of swelling.

## What it means for you

Real physical changes happen in the brain before menstruation that are related to hormones. However, these changes do not cause brain swelling, which means brain swelling is probably not the reason for neurological symptoms some women report before their period. The main limit is that only 20 women were studied.

20

women studied

19

had fluid increase before period

11.5 ml

average increase in fluid

## About the study

Original title Is cranial CSF volume under hormonal influence? An MR study Authors Grant R, Condon B, Lawrence A et al. Journal Journal of computer assisted tomography Year 1988 Study design Study Participants 20 Read the paper [doi.org/10.1097/00004728-198801000-00005](https://doi.org/10.1097/00004728-198801000-00005)

## Topics

[Premenstrual syndrome (PMS)](https://niyora.com/research/topics/condition-pms/)[Bloating, breast tenderness and physical symptoms](https://niyora.com/research/topics/symptom-physical-symptoms/)[Oral contraceptives and drospirenone](https://niyora.com/research/topics/treatment-hormonal-contraceptives/)[Perimenopause and menopause](https://niyora.com/research/topics/comorbidity-perimenopause/)

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