A sudden and temporary drop in blood pressure can cause nausea, dizziness and fainting. Although far less common than high blood pressure, people with low blood pressure might experience uncomfortable and potentially dangerous temporary drops in blood pressure after eating or standing too quickly.
Normal Blood Pressure
In terms of hypertension, any blood pressure lower than 120 over 80 is "normal." However, if it falls below 90 over 60, it becomes hypotension, or low blood pressure. For people with blood pressure that hovers at or just above hypotension, any change in blood pressure can lead to hypotensive symptoms like dizziness or fainting.
Meals
An August 2009 study published in the "American Journal of Clinical Nutrition" found that the consumption of food and water lowered blood pressure significantly more than the consumption of water alone. This study used a light breakfast rather than a large meal. However, an earlier study published in February 2006 in "The British Journal of Nutrition" compared the effects of meals that contain different amounts of fat and carbohydrates. Those findings suggest that heavier meals have a greater impact on blood pressure.
Other Factors
In addition to eating meals or getting up too quickly, dehydration is a significant risk factor for hypotension. You can easily experience dehydration by not drinking enough fluids on hot days or during exercise. Vomiting or diarrhea can also cause dehydration very quickly. Staying thoroughly hydrated by drinking water or an electrolyte is important to avoid hypotensive incidents.
Manage Your Blood Pressure
If you suffer spells of dizziness, nausea or fainting, see your doctor to rule out potentially serious problems. In addition to any intervention that your doctor prescribes, you can minimize the number and severity of low blood pressure incidents by drinking water or an electrolyte beverage 30 minutes before each meal. Drink them throughout the day to ensure sufficient hydration. You also can experiment with eating smaller meals more frequently to minimize the impact of large meals on your blood pressure. After eating, sit quietly for a few minutes to evaluate how you feel before you stand up, since the hypotensive effect of the meal will make you most vulnerable to passing out from standing up too quickly.
References
- MayoClinic.com; Low Blood Pressure (Hypotension); May 2011
- "The American Journal of Clinical Nutrition"; Acute Effects of Food on Postprandial Blood Pressure and Measures of Arterial Stiffness in Healthy Adults; Kiran D.K. Ahuja, et al.; August 2009
- "The British Journal of Nutrition"; The Hypotensive Response to Oral Fat is Comparable But Slower Compared with Carbohydrate in Healthy Elderly Subjects; R. Visvanathan, et al.; February 2006
- "American Journal of Hypertension"; Mechanisms Mediating Postprandial Blood Pressure Reduction in Young and Elderly Subjects; Kazuko Masuo, et al.; 1996
- National Heart Lung and Blood Institute; Diseases and Conditions Index: Hypotension
- "Nursing for Wellness in Older Adults"; Carol A. Miller; 2008
