Period Brain Fog: Is it *Really* a Thing?

This article was medically reviewed by Dr. Navya Mysore and updated on March 8, 2024

Do you feel kinda hazy in the run-up to your period or during your period? You’re not alone. Period brain fog is a legit thing, though it is not a recognized medical condition. 

And while there isn’t a ton of medical research into how pervasive this experience is, if you feel like you’re not firing on all cylinders mentally in the run-up to your period, it might help to know it’s just one of the many ways hormonal fluctuations/changing hormone levels give us the runaround!

What Is Brain Fog?

Brain fog is a general term used to describe a range of temporary cognitive symptoms, including difficulties with concentration, memory, and focus. If you’re in a brain fog, you may feel groggy or hazy, like your brain is not working as quickly as it typically does.

Brain fog can be caused by a variety of factors, including:

• Lack of sleep
• Stress
• Certain medications
• Hormonal changes (such as those around your period, or during perimenopause)
• Medical conditions such as chronic fatigue syndrome and fibromyalgia
• Mental health conditions such as depression and anxiety

Because the causes are so broad it can be challenging to pinpoint why you may be experiencing brain fog, but many people report experiencing it around their period.

Is Brain Fog Part of Premenstrual Syndrome (PMS)?

For some people, brain fog can be a part of premenstrual syndrome (PMS). PMS is a combination of physical and emotional symptoms that some people experience in the days or weeks leading up to their menstrual period. 

Premenstrual brain fog (brain fog before your period) is one of the cognitive symptoms that can occur during this time and may manifest with difficulty concentrating, forgetfulness, and feeling mentally sluggish.

The exact cause of PMS is not fully understood, and there is not a lot of medical research about the connection between periods and brain fog. But PMS and brain fog are believed to be related to hormonal changes that occur during the menstrual cycle.

The fluctuations in estrogen and progesterone can affect neurotransmitters in the brain, leading to cognitive symptoms such as brain fog.

What Causes Period Brain Fog?

Period brain fog might be closely tied to hormones, but we’re complex creatures and there can be many overlapping conditions that can cause brain fog around our period. Let’s look at some of the common causes of brain fog:

Hormones

During the menstrual cycle, levels of estrogen and progesterone fluctuate. These hormones can affect neurotransmitters such as serotonin, dopamine, and GABA, which are involved in mood regulation, attention, and memory.

These changes can lead to symptoms such as brain fog, difficulty concentrating, and forgetfulness. Pregnancy, postpartum, perimenopause, and menopause phases involve large hormonal shifts and can cause brain fog.

Insomnia and Poor Sleep

If you’re experiencing sleepless nights and wake up feeling groggy and unrested, you’ll be at risk of brain fog throughout your day. Menstruation can also disrupt sleep patterns, whether it’s period pains keeping you awake or has you up changing your pad, tampon, period undies, or emptying your menstrual cup. Lack of quality sleep around your period can exacerbate feelings of brain fog.

Chronic Fatigue Syndrome

Chronic Fatigue Syndrome (CFS) is a complex disorder that can cause a wide range of symptoms, including severe fatigue, muscle and joint pain, sleep disturbances, and cognitive impairment. Brain fog is a common symptom of CFS and menstruation can exacerbate symptoms of Chronic Fatigue Syndrome (CFS) for some people.

Individuals with CFS may also experience other cognitive symptoms such as difficulty concentrating, memory problems, and slowed information processing. These symptoms can be particularly challenging, as they can affect daily activities such as work, school, and the individual’s social life. 

Anxiety and Depression

Anxiety can cause brain fog by triggering the body's stress response. When the body is under stress, it releases hormones such as cortisol and adrenaline, which can impact your cognitive ability, causing forgetfulness, poor concentration, and mental exhaustion. 

This feeling will be familiar to many of us who have gone through anxious times: When you're dealing with increased stress levels, you can end up forgetting details of daily tasks, losing things more easily (where are my keys?!), etc. 

Depression and other mental health disorders can also cause brain fog by affecting your neurotransmitter balance. Low levels of serotonin, for example, can lead to symptoms such as fatigue, difficulty concentrating, and impaired memory.

Additionally, depression can cause changes in the structure and function of the brain, particularly in areas involved in cognitive processing and attention. 

If you experience anxiety or depression you may experience brain fog at any point during the month, but it may be compounded by the hormonal changes around menstruation.

Anemia

Anemia is a condition where there is a lower-than-normal number of healthy red blood cells (hemoglobin) in your bloodstream, which can lead to a reduced supply of oxygen. This can affect brain health and lead to symptoms such as fatigue, difficulty concentrating, and brain fog.

Anemia is more common in women especially in individuals who have a heavy menstrual flow. Iron is needed to produce hemoglobin and in women who have a heavy period flow they can lack iron and have iron deficiency anemia. Symptoms of iron deficiency include fatigue, weakness, shortness of breath, and pale skin.

If you suspect you are anemic, a quick blood test at your doctor's office will confirm your levels. Treatment for iron deficiency anemia may include iron supplements and/or dietary changes to increase iron intake.

Certain Medications

Certain medications can cause brain fog as a side effect. Some of the common types include:

• Antidepressants: Many antidepressants work by affecting levels of serotonin and other neurotransmitters in the brain. While these medications can be effective in treating depression and other mood disorders, they can also cause side effects such as fatigue, drowsiness, and difficulty concentrating.
• Anti-anxiety medications: Like antidepressants, anti-anxiety medications can affect neurotransmitter levels in the brain and cause side effects such as drowsiness, fatigue, and difficulty concentrating.
• Antihistamines: Antihistamines are commonly used to treat allergies, but they can also cause drowsiness,and difficulty concentrating. 
• Sleep medications: Medications used to treat insomnia, can cause drowsiness, confusion, and impaired memory.
• Opioid pain medications: Opioid medications are powerful pain relievers, but they can also cause drowsiness, confusion, and impaired cognitive function. 

Your healthcare provider and/or pharmacist should go over the possible side effects of any medications they prescribe. If these side effects are persistent or interfere with your ability to function, it’s important to discuss this with your doctor.

How to Address Period Brain Fog

If you feel like you experience brain fog around your period, there are some lifestyle changes you can make to mitigate the effects of temporary brain fog. However, if your brain fog is severe or interrupts your ability to function, it’s worth a trip to your doctor.

Maintain a Healthy Diet 

A healthy and balanced diet can help improve brain function by providing the brain with the nutrients it needs to function optimally. Here are some ways that a healthy diet can help:

• Providing essential nutrients: A healthy diet should include a variety of nutrient-dense foods such as fruits, vegetables, whole grains, lean protein sources, and healthy fats. These foods provide essential nutrients such as vitamins, minerals, and antioxidants that the brain needs to function properly.
• Regulating blood sugar: Eating a balanced diet that includes complex carbohydrates, protein, and healthy fats (avoiding refined sugars and carbohydrates) can help regulate blood sugar levels and prevent spikes and crashes that can contribute to brain fog.
• Reducing inflammation: Eating a diet that is rich in anti-inflammatory foods such as fruits, vegetables, nuts, and fatty fish can help reduce inflammation in the body and improve brain function.
• Promoting gut health: The gut-brain connection is a two-way street, and a healthy gut can help improve brain function. Eating a diet that is rich in fiber, prebiotics, and probiotics can help promote the growth of beneficial gut bacteria.

Some specific foods that have been shown to improve brain function and reduce symptoms of brain fog include fatty fish, nuts and seeds, berries, leafy greens, eggs, and whole grains. If you're planning to make big changes to your diet, it's always worth checking in with your healthcare provider.

Avoid Alcohol or too Much Caffeine

If your morning coffee helps kick start the day, it may feel intuitive that more coffee can help with period brain fog. Actually, while caffeine is a stimulant that can temporarily improve alertness and cognitive function, in excessive amounts, caffeine can lead to symptoms such as anxiety, jitteriness, and insomnia, which can exacerbate brain fog.

If you notice your caffeine intake is making your brain fog worse, you might want to consider reducing the number of cups you have per day.

Alcohol, on the other hand, is a depressant that can slow down brain function and impair cognitive function. Even small amounts of alcohol can affect cognitive function and lead to symptoms such as worse memory, lowered mood, and difficulty concentrating.

It is important to consume caffeine and alcohol in moderation and be aware of how they affect your cognitive function. If you experience symptoms of brain fog or other cognitive impairment after consuming caffeine or alcohol, it may be helpful to reduce your intake of these substances

Get Some Exercise, Even if It’s Gentle

Exercise has many benefits for brain function, including reducing symptoms of brain fog, whether in general or around your period. Exercise can also help with period pain. Here are some ways that exercise can help brain fog:

• Increases blood flow and oxygen to the brain
• Reduces stress and anxiety: Exercise is a natural stress reliever!
• Boosts mood: Exercise has been shown to release endorphins
• Improves sleep: Exercise can help improve the quality and duration of sleep
• Promotes brain plasticity: Exercise has been shown to promote brain plasticity, or the brain's ability to adapt and change in response to new stimuli. This can help improve cognitive function and reduce symptoms of brain fog.

Try to Get Good Quality Sleep

Good quality sleep is essential for overall cognitive function and can help reduce symptoms of brain fog. Seven to nine hours is considered ideal. If you sleep poorly during your period, try the following:

• Practice good sleep hygiene: Maintain your regular sleep schedule, create a relaxing sleep environment, and avoid electronic devices before bedtime. Yes we mean it: Put down the phone!
• Manage menstrual pain and discomfort: If menstrual cramps or discomfort interfere with your sleep, try using heat therapy (i.e. a hot water bottle), over-the-counter pain relievers, or prescription medications as directed by your healthcare provider.
• Use comfortable bedding and clothing: Choose comfortable, breathable bedding and clothing to help regulate your body temperature and reduce discomfort.
• Avoid caffeine and alcohol: Reduce caffeine and alcohol consumption before bedtime, as they can interfere with sleep quality.
• Stay physically active: As already discussed, regular exercise can help improve sleep quality and reduce symptoms of menstrual discomfort.
• Consider natural remedies: Some natural remedies, such as herbal teas, aromatherapy, meditation or relaxation techniques, may help improve sleep quality.

Track Your Brain Fog (and Other Menstrual Cycle Symptoms)

Because brain fog leaves you feeling, well, foggy… you may struggle to recall if there are patterns or connections between your menstrual cycle and experiences of brain fog, whether that's mental clarity or mental energy.

We all tend to be unreliable narrators of our physical symptoms when relying on memory. But that doesn’t mean you should be dismissive of your experience. 

Instead, use a period app or journal to track your physical and mental symptoms. If you feel like hormone fluctuations, sleep or diet, medications, or your emotional states also contribute to brain fog, track those too. It can be helpful to find correlations between diet and exercise, for example, and PMS symptoms. 

Having some tracking in place will also equip you for any conversations you may have with your healthcare provider.  

Get Bloodwork Done

If you experience persistent brain fog, you should see your doctor and investigate your symptoms. Blood work can be helpful to identify if you have any deficiencies, like iron deficiency anemia.

Iron deficiencies or low vitamin D levels are easy enough to remedy with a supplement. Your doctor will help advise you on the appropriate dosage and any follow-up tests.

Talk with Your Doctor

More generally, do discuss persistent feelings of brain fog with your doctor. While there isn’t a ton of medical research on brain fog, a good doctor will listen closely to your experience and find ways to support you emotionally and physically. Just knowing you’re not alone in experiencing period brain fog may be a great first step!

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7226433/ 

https://www.mayoclinic.org/diseases-conditions/premenstrual-syndrome/symptoms-causes/syc-20376780

https://www.cedars-sinai.org/health-library/diseases-and-conditions/a/overview-of-anemia.html 

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We hope you found this post informative—but remember: we’re not doctors and this post is not medical advice! While all posts are fact-checked and well researched, we always recommend you chat with your doctor about any questions or concerns you might have regarding a medical condition. 

We’re here to support and educate, but never with the aim of disregarding professional medical advice you’ve been given. Phew, now that that’s out of the way, you can go on living unapologetically free.