From the Guidelines
Fogginess is primarily caused by cognitive difficulties, such as difficulty concentrating or short-term memory loss, which can be symptoms of various underlying conditions, including vitamin B12 deficiency, as noted in the most recent study from 2024 1.
Causes of Fogginess
The causes of fogginess can be multifactorial, including:
- Cognitive impairment due to vitamin B12 deficiency, which can lead to symptoms such as difficulty concentrating or short-term memory loss, sometimes described as "brain fog" 1
- Neurological and cognitive symptoms associated with long COVID, including sensorimotor symptoms, memory loss, cognitive impairment, and paresthesia 1
- Cognitive impairment in people living with HIV, which can be caused by a direct effect of HIV on the brain, as well as comorbidities and medication effects 1
- Systemic mastocytosis, which can cause neurological symptoms such as headache, poor concentration and memory, and brain fog 1
Key Findings
- A meta-analysis found that cognitive impairment was present in 22% of patients with COVID-19 at 12 weeks after infection, and may increase over time 1
- Activation of the kynurenine pathway has been identified in long COVID, and is associated with cognitive impairment 1
- Cognitive impairment has been found in individuals who recovered from COVID-19, and at higher rates when objective versus subjective measures were used 1
Recommendations
Based on the most recent and highest quality study, it is recommended to investigate and address underlying conditions such as vitamin B12 deficiency, long COVID, and cognitive impairment in people living with HIV, in order to manage and prevent fogginess 1.
From the Research
Causes of Fogginess
- Brain fog can be caused by a lack of sleep, poor nutrition, medications, or drugs 2
- Neuroinflammation is also a common cause of brain fog, with chronic low-level inflammation being the most detrimental to the mind and body 2
- Sleep disorders, such as insomnia, restless legs syndrome, and narcolepsy, can also contribute to fogginess 3, 4
- Certain medications, including antidepressants, can affect sleep and contribute to fogginess 5
- Iron deficiency has also been linked to sleep disorders and fogginess, with iron supplementation showing promise as a treatment 6
Underlying Factors
- Lack of sleep and poor sleep quality can exacerbate fogginess 3, 4
- Poor nutrition and lifestyle habits can also contribute to fogginess 2
- Underlying medical conditions, such as neurological disorders, can also increase the risk of fogginess 4
- Certain medications and substances, such as sedatives and stimulants, can affect sleep and contribute to fogginess 5