Interactive tool · Symptom checker
Brain-Fog Cause Finder
Brain fog is a symptom, not a diagnosis — and it usually has a contributor you can name. Tick the symptoms and context that fit you, and this tool surfaces the likely drivers, ranked, each with a short evidence-based note. When a result is medical — iron, B12, thyroid, blood sugar — it tells you plainly to get the bloodwork. It is a way to know what to test and what to raise with a clinician, not a verdict.
Read before you use this
This is an educational symptom organizer, not a diagnosis and not a substitute for a clinician. It cannot examine you, see your medical history, or run a single blood test — it only sorts the boxes you tick against patterns described in our articles. Several causes of brain fog overlap, look alike, and can co-occur, and some serious conditions are not covered here at all. Do not start, stop, or change any supplement or medication based on this tool. Persistent, sudden, or worsening fog — especially with chest pain, severe headache, confusion, weakness or numbness on one side, trouble speaking, fainting, or thoughts of self-harm — needs urgent in-person care. For everything else, bring your results to a licensed clinician and ask about the specific tests it names.
Tick the symptoms and context above that match you, and the likely contributors will appear here — ranked, each with a short note and a clear next step.
Go deeper
Each result links to its own deep dive. These three are the best places to widen the picture.
This tool is informational and not medical advice. It does not diagnose any condition and cannot replace testing and a clinician's judgment. The contributors it surfaces are common patterns, not a complete list, and your fog may have a cause it does not cover. Talk to a licensed clinician about persistent or worsening symptoms — and get the bloodwork it points you toward before acting on any of it.