11mths postpartum... recent symptoms: dizzy spells, foggy vision, exhaustion, random mild headaches. what could be going on?

Long Differential Dx: Though nonspecific, dizzy spells, foggy vision, exhaustion and random mild headaches, could indicate diabetes mellitus, hypertension, kidney disease, vertebrobasilar insufficiency, intracranial hypertension or even a worse diagnosis. Try to have this evaluated by a qualified provider, since some of these possibilities would demand university-level care.