Unfortunately many more people have heard about brain fog because of the pandemic and long COVID.

But the symptom was first mentioned centuries ago, and has been associated with dozens of conditions.

Norman and Tegan try to define brain fog, and explain why it can be difficult to treat.

References:

• What is brain fog? - BMJ neuropsychiatry
• Subjective brain fog: a four-dimensional characterization in 25,796 participants
• Comprehensive Clinical Characterisation of Brain Fog in Adults Reporting Long COVID Symptoms
• Understanding the Experience and Impacts of Brain Fog in Chronic Pain: A Scoping Review
• Low-dose naltrexone use for the management of post-acute sequelae of COVID-19
• ‘Brain fag’: a syndrome associated with ‘overstudy’ and mental exhaustion in 19th century Britain