“Extreme nausea, a severe headache caused by blood clots in the head, and excessive uncontrollable hiccups are three early warning signs that precede a stroke." (Video transcript adds: "These are different than symptoms from an actual stroke" and "The absolute best way to avoid these early signs, or even to avoid strokes in general, is to…”

Authoritative sources list nausea, severe headache, and hiccups as possible stroke symptoms, not as a separate category of warning signs occurring before a stroke. CDC lists the core signs as sudden trouble walking, dizziness, loss of balance, or lack of coordination; sudden trouble seeing; sudden numbness or weakness in the face, arm, or leg, especially on one side of the body; sudden confusion, trouble speaking, or difficulty understanding speech; and sudden severe headache with no known cause. Hiccups and nausea do not appear in the CDC's primary list. Hospital-system patient education does include them among less common presentations: Northwestern Medicine lists sudden nausea or vomiting not caused by a viral illness among less common stroke symptoms, and Banner Health includes hiccups among warning signs. The strongest peer-reviewed evidence concerns hiccups as a presenting feature of brainstem stroke, specifically lateral medullary (Wallenberg) infarction. In a lesion-mapping study of lateral medullary infarction patients, there were 11 (35.5%) patients with hiccups, and voxel-based lesion-symptom mapping showed the dorso-lateral region of the middle medulla was significantly associated with hiccups. Case reports describe ischemic area postrema syndrome presenting with intractable nausea, vomiting, and hiccups, with imaging confirming lateral medullary infarcts. A case series found four patients with brainstem lesions presenting with intractable hiccup and mild to moderate neurological signs, two initially diagnosed as psychogenic. In all of these, the hiccups and nausea were caused by a stroke that had already occurred, not by a state preceding one. The recognized medical event that genuinely precedes a stroke is a transient ischemic attack. The American Stroke Association states a TIA is often called a mini-stroke but is really a warning stroke, and TIA and stroke symptoms are the same, although most TIA symptoms last only a few minutes, up to 24 hours, adding that TIAs occur before approximately 15% of all strokes. NINDS states there is no immediate way to tell whether symptoms are from a TIA or a stroke. On the hiccups-in-women point often circulated online, the original Ohio State source carries a qualifier the viral framing drops: the survey found only 10 percent were aware that hiccups combined with atypical chest pain are among the early warning signs of a stroke in women when accompanied by or followed by typical stroke symptoms. Note also that this is a public-awareness survey of 1,000 women, not a study establishing predictive value. On diet, the AHA/ASA guideline recommends a different pattern than the one in the post: in patients with stroke and TIA, it is reasonable to counsel individuals to follow a Mediterranean-type diet, typically with emphasis on monounsaturated fat, plant-based foods, and fish consumption, and low-salt and Mediterranean diets are recommended for stroke risk reduction. Low-carbohydrate evidence is observational and mixed: one cohort reported that a moderate level of animal-based low-carbohydrate diet, but not a plant-based low-carbohydrate diet, was associated with a lower risk for stroke, while a separate large cohort found an adverse effect of a low-carbohydrate diet on atrial fibrillation, with people on a low-carbohydrate diet possibly having a higher risk of incident atrial fibrillation. Atrial fibrillation is itself a major cause of embolic stroke.