Postprandial hypotension is low blood pressure after a meal. This condition can manifest itself as dizziness or lightheadedness that affects nearly one-third of older men and women.
Proper digestion is accomplished when the functioning of the digestive, nervous, and circulatory systems are precisely coordinated. Extra blood is directed to the intestines and stomach. To compensate for this diversion of blood circulation, the heart beats faster and blood vessels narrow. This helps maintain blood pressure to other parts of the body.
If the blood vessels and the heart do not respond the way they should, you may experience low blood pressure elsewhere in the body while the digestive organs are completing the process of digestion. This can lead to symptoms associated with low blood pressure.
Although researchers and doctors know how postprandial hypotension occurs, they are unsure why. The condition itself is caused by the pooling of blood in abdominal organs during the digestive process. As a result, less blood is available for circulation and the blood pressure drops upon standing.
It is normal for some blood to pool in the abdominal organs, but in the case of postprandial hypotension, this pooling becomes exaggerated.
Eating certain foods—with carbohydrates being a notable example—has been seen to worsen postprandial hypotension. This has led some researchers to believe that people with postprandial hypotension release insulin as a response to ingested carbohydrates. This contributes to the drop in blood pressure and doesn’t allow circulation to be compensated.
Symptoms of postprandial hypotension include dizziness, lightheadedness, and weakness upon standing up within 30 to 60 minutes after consuming a meal. Symptoms may be more severe after consuming a larger meal or eating a meal that includes more carbohydrates or alcohol.
You can’t really do anything about your postprandial hypotension, but you can prevent it. Postprandial hypotension can be prevented by consuming water before meals, cutting portion size, consuming less rapidly digested carbohydrates (which includes white rice, potatoes, highly refined flour, and sugary beverages), or waiting between 30 to 60 minutes before getting up after a meal.
If you find that these measures are not working for you, other treatments used for orthostatic hypotension may help. These include taking nonsteroidal anti-inflammatory drugs (NSAIDs) before meals. They can help retain more salt, thereby increasing blood volume. The use of caffeine, commonly found in coffee, may also help constrict blood vessels, helping to reduce hypotensive symptoms. Guar gum can also help by slowing down the emptying of the stomach after a meal.
Improving vascular tone through exercise can help diminish the symptoms of postprandial hypotension. If you are taking certain medications, such as diuretics, they may be the source of your postprandial hypotension. By stopping them, you may dramatically improve your symptoms. However, it is highly advised to speak to your doctor first before modifying any existing drug regimen.
There exists another treatment that can help control postprandial hypotension—subcutaneous injections of octreotide before meals. This drug behaves like somatostatin, a hormone produced by the pancreas that helps to reduce the amount of blood flow to the intestines. This treatment is expensive and can cause significant side effects.