Brain Fog: What Is It And How Can It Be Overcome?

Overview

Cognition refers to an individual’s thinking skills, learning abilities, memory, awareness of surroundings, and judgment. People might face different challenges with their thinking skills, which can originate from various factors, such as post-COVID-19 effects. These challenges include memory, attention, information processing, planning, and organisation.

Brain fog is a non-medical term used to describe a spectrum of symptoms such as: feeling confused, having poor concentration, and slow or fuzzy thinking. Brain fog can be exacerbated by fatigue, meaning that the more tired a person is, the more they experience cognitive challenges. Its symptoms vary among people and may change over time.

This article discusses common causes of brain fog, such as hormonal changes, chemotherapy, diabetes, and COVID-19, and suggests actions to alleviate it.

What do people experience when they talk about brain fog?

Brain fog can feel slightly different from person to person. People may experience the following symptoms with brain fog:

• Difficulty concentrating or focusing
• Forgetfulness
• Confusion
• Fatigue
• Losing track of their thoughts
• Mental exhaustion
• Trouble finding words
• Slow thought process and reaction time

What causes brain fog?

Hormonal changes

Hormonal changes during pregnancy, perimenopause and menopause may contribute to brain fog.

Studies on cognitive changes during pregnancy are controversial. Most indicate cognitive impairment, while others report an improvement or no effect at all. Commonly reported challenges include:

• poor concentration
• memory decline
• disorientation
• difficulties with executive function

However, most of the available data focuses on memory decline and a decrease in focus during pregnancy, while data regarding language abilities is limited.¹

Cognitive complaints are common among women during the period of menopause and are connected to a decline in quality of life. These issues are well documented and confirmed throughout the menopausal transition.

Research indicates that hormonal changes during menopause, particularly the substantial decrease in oestrogen levels, significantly contribute to cognitive impairments. Additionally, other symptoms of menopause like vasomotor symptoms (VMS), the so-called hot flashes, sleep problems, and mood changes further contribute to these cognitive challenges. 

According to a review published in the journal Climacteric in 2022, brain fog in the period of menopause can be defined as follows: the combination of cognitive symptoms experienced by women around the menopausal period, which more frequently result in memory and attention difficulties, and involve such symptoms as difficulty recalling words or names, being easily distracted, forgetting intentions (e.g. the reason for entering a specific room), and trouble switching between tasks.²

Long COVID

Regarding post-COVID-19 syndrome (also known as long COVID) brain fog, studies show that the COVID-19 virus can enter the gastrointestinal tract and infect intestinal epithelial cells, causing local inflammation. Mucosal immune cells, located within the mucosal lining of the gastrointestinal tract— a layer that coats the inner surface of the gastrointestinal tract—can enter the bloodstream and reach the central nervous system. This can impact the brain and cause decreased mental ability and brain fog.³

Chemotherapy

A study published in the Annals of Oncology in 2015 highlighted the prevalence of chemotherapy-associated cognitive changes among early-stage breast cancer survivors. The authors suggested that chemotherapy drugs are unlikely to be a direct cause, as they likely cannot penetrate the blood-brain barrier due to their size. Instead, they proposed that neurotoxicity may be linked to proinflammatory cytokines, similar to the cytokine storm observed in some people with COVID-19.

In the brain, cytokines can cause local inflammation through reactions involving oxygen and nitric oxide, particularly in regions like the hippocampus and areas rich in cytokine receptors. These reactions consequently lead to cognitive changes, including memory lapses, and changes in attention, processing speed, and response speed.⁴

Diabetes

Research indicates that middle-aged and older people with type 2 diabetes may experience a decline in cognitive function, suggesting accelerated brain ageing and an increased risk of dementia. Type 2 diabetes is known to affect two key cognitive domains: 

• Episodic memory, which involves acquiring, storing, and recalling personal experiences such as events and specific details
• Executive function, which encompasses skills such as working memory, speech fluency, processing speed, mental flexibility, and cognitive control 

A study revealed that among older women with type 2 diabetes, there was a rapid decline in executive function, which includes skills like memory and problem-solving. In contrast, women over 80 years old, who do not have type 2 diabetes tend to maintain better cognitive abilities.⁵

Other causes

Other possible causes of brain fog include:

• Autoimmune conditions like fibromyalgia, multiple sclerosis and lupus
• Mental health conditions like anxiety and depression
• Poor nutrition, stress, lack of sleep
• Long hospital stays

What is the treatment for brain fog?

There is no specific treatment for brain fog. To help clear the brain fog, healthcare professionals recommend engaging in activities that boost the immune system and help with thinking and memory.

Some actions one can take to alleviate brain fog are:

• Engage in aerobic exercise. It's commonly advised to engage in aerobic exercise for a minimum of thirty minutes a day, five days a week
• Follow a Mediterranean diet. A healthy diet including olive oil, fruits and vegetables, nuts and beans, and whole grains has been shown to enhance thinking, memory, and overall brain health
• Avoid alcohol and drugs. The brain needs to heal, so substances that can adversely affect it should be avoided
• Improve sleep habits. Not getting sufficient sleep or good-quality sleep can cause problems with focusing on tasks and thinking clearly. During sleep, the brain and body detox and focus on healing
• Participate in social activities. Social activities benefit mood and also contribute to improved thinking and memory
• Engage in other beneficial activities such as listening to music, practicing mindfulness, and maintaining a positive mental attitude
• Attend therapy sessions like cognitive behavioural therapy (CBT)
• Taking short breaks, throughout the day, of around 30 minutes each, helps prevent overworking the brain

If these recommendations don’t resolve brain fog, a healthcare provider could manage specific symptoms by prescribing medications like antidepressants or nonsteroidal anti-inflammatory drugs (NSAIDs), among others.

How long does brain fog last?

Brain fog can last anywhere from days to weeks and, in some cases, persist for months or even years. People who experience brain fog should contact their healthcare provider if it interferes with their quality of life. They can provide advice on treatment options to reduce its impact.

Summary

Brain fog – a condition that affects thinking, memory, and concentration – can create obstacles in daily activities. It is usually temporary but can vary in duration. Cognitive challenges, often resulting from post-COVID-19 effects, hormonal changes, chemotherapy, and type 2 diabetes, manifest as confusion, poor concentration, and slow thinking.

Hormonal fluctuations during pregnancy and menopause, inflammation from long COVID, chemotherapy-induced neurotoxicity, and diabetes-related cognitive decline are notable contributors. Other factors contributing to brain fog include autoimmune disorders, mental health issues, poor nutrition, stress, lack of sleep, and prolonged hospital stays. 

Treatment focuses primarily on lifestyle changes rather than specific medical treatments. Recommended steps include regular aerobic exercise, adopting a Mediterranean-style diet, avoiding alcohol and drugs, improving sleep quality, participating in social activities, and attending cognitive-behavioural therapy sessions. Taking short breaks throughout the day can also be helpful. If these adjustments do not lead to improvement, healthcare providers may prescribe medications to manage specific symptoms.