For how we live.
4 articles published between September 16, 2026 and September 24, 2026.
"Brain fog" is a lay term for trouble concentrating and remembering, not a disease. Common drivers include poor sleep, low mood, the menopause transition, thyroid or B12 problems, and the tail of an infection.
A limb that has "gone to sleep" is brief pressure on a nerve and clears in minutes. Tingling that is persistent or spreading can mean carpal tunnel, diabetes or low B12; sudden one-sided numbness is an emergency.
Classic B12 deficiency is relatively uncommon, but it clusters: in people over 50 whose absorption fails, in vegans whose intake does, and around metformin, acid-lowering drugs and stomach surgery.
Adults need about 2.4 micrograms a day, and most meat-eaters get it easily. Real deficiency clusters in older people, whose absorption fails, and in vegans, whose intake does.