Brain Fog Before My Period: Is It PMS or Something Else?

You're not imagining it. You may be more forgetful before your period.

If you've ever experienced brain fog before your period, you're not alone. Brain fog—when you can't think clearly, forget things, or start making simple mistakes—is a common symptom experienced by people during their menstrual cycle.

There are some potential reasons why period-related brain fog may happen, such as hormone fluctuations. However, that sluggish, cloudy feeling you get in your head affects everyone differently. Here's more about brain fog and its connection to a person's period.

How Do You Know It's Brain Fog?

According to a 2021 study published in the Journal of Psychosocial Nursing and Mental Health Services, brain fog is clinically referred to as "cognitive difficulties." Brain fog does not exclusively affect when you are premenstrual, though that is a common time to experience it. The condition can also be a response to lack of sleep, poor nutrition, medications, drugs, or health-related issues like long COVID.

Despite how common it is, a study published in 2013 in Frontiers in Physiology noted that brain fog (which is experienced as slow thinking, difficulty focusing, confusion, lack of concentration, forgetfulness, or haziness in thought) is not fully understood.

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Before Your Period

Many people report brain fog, or trouble thinking or focusing, as a symptom just before their period. We can understand this by considering how hormones fluctuate during the menstrual cycle. We know hormones like estrogen and proestrogen seem to influence how the brain functions. In a typical cycle, progesterone levels rise in the two weeks leading up to your period; that has been linked to a drop in serotonin, a neurotransmitter that boosts mood and helps keep you sharp.

In some cases, brain fog is experienced as a symptom of premenstrual dysphoric disorder (PMDD). PMDD takes place in the week or two before your period starts, as hormone levels begin to fall after ovulation. The Office on Women's Health (OWH) defines PMDD—a condition affecting up to 5% of women of childbearing age—as a condition that causes more severe symptoms than PMS, including severe depression, irritability, and tension.

Unsettled Science

However, the science is still unfolding on the effect of the fluctuating hormones of the menstrual cycle on the brain. A 2017 study published in Frontiers in Behavioral Neuroscience examined the impact of menstrual cycle hormones and brain functioning. Researchers at University Hospital Zurich in Switzerland followed 68 participants over two menstrual cycles and had them complete a series of cognitive tests. At various stages of their cycle, participants' memory, bias, and multitasking skills were tested. The study results showed that changes in hormone levels (estrogen, progesterone, and testosterone) were not associated with changes in performance on any cognitive tests.

In addition, the authors of a 2020 study published in Brain Sciences explored the role of sex hormones on cognition during the menstrual cycle. They describe the menstrual cycle as "a convenient model " to look at how changing levels of these hormones can affect the brain and cognitive functioning. However, they concluded that future studies are needed to be clear on the role of sex hormones and brain functioning.

Anemia and Brain Fog

Another cause of brain fog is iron deficiency anemia. Iron deficiency anemia is the most common type of anemia. This condition happens when your body does not make enough healthy red blood cells or the blood cells do not work correctly.

Because iron-deficiency anemia can happen when you lose a lot of blood due to heavy periods, anemia symptoms can appear to be more severe during your period.

According to the OWH, iron-deficiency anemia can cause serious health problems if left untreated. With anemia, the heart must work harder to compensate for the lack of red blood cells or hemoglobin. This extra work can harm the heart.

Your healthcare professional can check your levels with a quick blood test, and if you're anemic, they will likely prescribe supplements. It's also a good idea to add more iron-rich foods, such as red meat, leafy greens, egg yolks, and beans, to your plate. Vegetarians are particularly prone because most people get iron from animal products.

Beating Period Brain Fog

There aren't any treatments specifically tailored to period-related brain fog. Still, if you know you are susceptible to brain fog, you can take certain proactive steps to minimize the symptoms. According to a November 2021 article published in The Journal of Psychosocial Nursing and Mental Health Services, you may be able to relieve brain fog using methods such as:

  • Engaging in cognitive retraining (where you can find ways to improve cognitive skills like memory or concentration)
  • Being physically active
  • Maintaining a healthy diet
  • Managing stress

You can also monitor your cycle, so you know when you'll be most apt to feel dull. On those days, you can be diligent about things you have to do or places you have to go by writing things down in your day planner or setting reminders on your electronic devices, for example.

When you're aware that you may be likely to experience brain fog before your period, that may also be a great time to prioritize shut-eye even more. Getting behind with sleep has the potential to lead to brain fog: A Journal of Clinical & Diagnostic Research study published in August 2017 found that individuals who were sleep-deprived were less alert and performed worse cognitively. However, with good sleep habits, as recommended by the Centers for Disease Control and Prevention (CDC), you should feel more refreshed and sharp.

However, if you find that you are consistently having issues with brain fog, talking with a healthcare professional may be necessary to determine if there are any other underlying causes for your experiences of brain fog.

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