Sjogren's syndrome is a fairly rare autoimmune disease that can cause a wide variety of symptoms, including brain fog. Brain fog is medically defined as "a subjective sensation of mental confusion and difficulty concentrating." It can be caused by many things, including infections, medications, and various medical conditions. Sjogren's syndrome is one of those conditions.
While not everyone with Sjogren's experiences brain fog, it is a fairly common symptom. If you are experiencing this symptom, it is important to discuss it with your doctor. There may be treatments available that can help lessen the severity of the brain fog and make it easier for you to function day-to-day.