"foggy thinking" means having trouble focusing or thinking clearly. It's like when your mind feels a bit hazy or cloudy, making it hard to make decisions or understand things clearly. Full definition
There are a number of ways inadequate circulation can inhibit brain function and cause foggy thinking. (drjockers.com)
That means foggy thinking and frequent «where did I put my keys» moments. (maryvancenc.com)
The National Foundation for Celiac Awareness notes that people with gluten sensitivities report foggy thinking, ADHD - symptoms, and even depression — all of which are believed to be connected to the inflammatory compounds released when they eat gluten. (annmariegianni.com)