What is brain fog?
Brain fog itself is not a medical condition but instead a symptom of other medical conditions. It’s a type of cognitive dysfunction involving:
memory problems
a lack of mental clarity
poor concentration
an inability to focus
Some people also describe it as mental fatigue. Depending on the severity of brain fog, it can interfere with your work, school, or other daily tasks. But it does not have to be a permanent fixture in your life.
We’ve partnered with C60 Power to discuss six possible causes of brain fog.
What are the causes of brain fog?
There are several reasons why brain fog may happen. Once you figure out the underlying cause, you can begin managing it.
Here are six possible causes:
1. Stress
Chronic stress can increase blood pressure, weaken the immune system, and trigger depression, according to a 2017 review of research. It can also cause mental fatigue.
When your brain is exhausted, it becomes harder to think, reason, and focus.
2. Lack of sleep
Poor sleep quality can interfere with how well your brain functions, according to 2021 research. The goal is to usually aim for 8–9 hours of sleep every night.
Sleeping too little can lead to poor concentration and cloudy thoughts.
3. Hormonal changes
Research from 2018 suggests hormonal changes can also cause brain fog.
Levels of the hormones progesterone and estrogen increase during pregnancy. This change can affect memory and cause short-term cognitive impairment.
Similarly, a drop in estrogen levels during menopause can cause forgetfulness, poor concentration, and cloudy thinking, according to 2019 research.
4. Diet
Diet can also play a role in brain fog.
Vitamin B12 supports healthy brain functioning. A 2021 research review found that a vitamin B12 deficiency can affect cognitive function and bring about brain fog.
If you have food allergies or sensitivities, brain fog may develop after eating certain foods. These include:
aspartame
peanuts
dairy
Removing trigger foods from your diet may improve symptoms.
5. Medications
If you notice brain fog while taking medication, talk with your doctor. Brain fog is a known side effect of certain medications, such as certain sleep and pain medications. Lowering your dosage or switching to another drug may improve your symptoms.
Brain fog can also occur after cancer treatments. This is referred to as chemo brain.
6. Medical conditions
Medical conditions associated with inflammation, fatigue, or changes in blood glucose levels can also cause mental fatigue.
For example, brain fog is a symptom of chronic fatigue syndrome (CFS), which involves persistent fatigue for a prolonged period of time, according to 2020 research.
According to a 2015 research review, people who have fibromyalgia may experience similar fogginess on a daily basis.
Other conditions that may cause brain fog include:
anemia
depression
diabetes
migraine
hypothyroidism
autoimmune diseases, like lupus, rheumatoid arthritis, Sjögren’s syndrome, and multiple sclerosis
dehydration
viral infections like COVID-19
How it’s diagnosed
Talk with a doctor if you have a persistent lack of clarity that worsens or does not improve.
A single test cannot be used to diagnose brain fog. Brain fog may signal an underlying issue, so healthcare professionals will conduct a physical examination and ask about your:
mental health
diet
level of physical activity
current medications or supplements
You should let a doctor know about other symptoms you might have. For example, someone with hypothyroidism may have brain fog along with hair loss, dry skin, weight gain, or brittle nails.
Blood work can help your doctor identify the cause of your brain fog. A blood test can detect the following:
irregular glucose levels
poor liver, kidney, and thyroid functions
nutritional deficiencies
infections
inflammatory diseases
Based on the results, your doctor will determine whether to run further tests. Other diagnostic tools may include imaging tests to look inside the body, like X-rays, magnetic resonance imaging (MRI), or computerized tomography (CT) scans.
Your doctor may also conduct allergy testing to check for allergies or a sleep study to rule out a sleep disorder.
Keeping a food journal can help you determine if your diet contributes to brain fog.
Treating brain fog
Brain fog treatment depends on the cause. For example, if you have anemia, iron supplements may increase your production of red blood cells and reduce your brain fog.
If you’re diagnosed with an autoimmune disease, a doctor may recommend a corticosteroid or other medication to reduce inflammation or suppress the immune system.
Sometimes, relieving brain fog is a matter of correcting a nutritional deficiency, switching medications, or improving the quality of your sleep.
You can try these strategies at home to relieve brain fog:
Get at least 8–9 hours of sleep every night.
Manage your stress levels, knowing your limitations. Find activities you enjoy doing and try to make time for them.
Avoid excessive alcohol and caffeine.
Exercise regularly, but not too close to bedtime.
Strengthen your thinking abilities — you can try volunteering or solving brain puzzles.
Increase your intake of protein, fruits, vegetables, and healthy fats.
What is the outlook for brain fog?
Brain fog can be frustrating, but relief is possible. You should not ignore your symptoms because, if left untreated, brain fog can impact the quality of your life.
Once the underlying cause is addressed, your mental clarity can improve.