An Overview of Postprandial Hypotension

Postprandial hypotension is a condition in which a person’s blood pressure drops after they eat. In fact, “postprandial” means “after a meal.”

For people who have postprandial hypotension, the simple act of standing up after a meal can produce a dramatic drop in blood pressure, triggering significant symptoms.

This article explains that postprandial hypotension is more common among older adults. It also spells out the symptoms, causes, and treatment of the condition.

Condition Trends to Older Adults

Postprandial hypotension is most commonly seen in older adults. Up to one in three of them will have some degree of postprandial hypotension, defined as a drop in the systolic blood pressure of up to 20 mmHg within two hours after a meal.

For most of these individuals, the condition is mild and does not trigger symptoms. In some people, however, postprandial hypotension can become quite serious.

Postprandial hypotension is one particular form of orthostatic hypotension (a drop in blood pressure while standing up). All types of orthostatic hypotension are more likely to affect people with high blood pressure, or with certain conditions that impair the autonomic nervous system, such as Parkinson's disease and diabetes.

Symptoms of Postprandial Hypotension

People who have postprandial hypotension often experience lightheadedness, dizziness, weakness, or even syncope (loss of consciousness) when they stand up within one or two hours after eating a meal.

Symptoms tend to be more severe after eating a large meal or one that is heavy in carbohydrates. Consuming alcohol before or during a meal can be another contributor. These symptoms usually resolve within two hours or so after finishing a meal.

Causes of Postprandial Hypotension

While the cause of postprandial hypotension is not completely understood, it is thought to be related to the pooling of blood in the abdominal organs during the process of digestion.

As a result of this pooling, the amount of blood available to the general circulation decreases, causing a drop in blood pressure. Standing up increases this effect.

Some amount of blood accumulation in the abdominal organs after a meal is normal since digesting food requires an increase in blood flow. To compensate, the blood vessels in the legs naturally constrict as a reflex.

High-Carb Foods

Eating high-carbohydrate meals appears to worsen postprandial hypotension. This observation has led some experts to theorize that, in people with postprandial hypotension, insulin or other blood chemicals that are released in response to a high-carb meal may cause excessive dilation of the abdominal blood vessels.

Aging

To some extent, aging is accompanied by an increase in the abdominal blood pooling that normally occurs after a meal. Most older people never develop symptoms from this increased blood pooling. But people who experience significant symptoms from postprandial hypotension tend to be older.

Treatment

While there is no specific treatment to eliminate postprandial hypotension, most people can learn to control the symptoms. Treatment involves four elements:

• Eat smaller, more frequent meals. Eating large meals tends to exaggerate abdominal blood pooling. Smaller meals mean less blood pooling.
• Avoid high-carbohydrate foods or those that include bread, pasta, and potatoes. (Be sure to do your research as you do your meal planning. Even fruits that are good for you like apples, mangoes, pears, and raisins are high in carbs.)
• Avoid alcohol. Alcohol relaxes blood vessels and tends to prevent the constriction of blood vessels in the legs that would normally compensate for abdominal blood pooling.
• Stay seated. Or, if symptoms are severe, lie down for an hour or two after eating. Abdominal blood pooling tends to dissipate within this time period after a meal.

If these measures are insufficient, other therapies commonly used to treat orthostatic hypotension are often helpful. These include:

• NSAIDs: Taking a nonsteroidal anti-inflammatory drugs (NSAIDs) prior to a meal can cause salt to be retained, thereby increasing blood volume.
• Caffeine: This can cause blood vessels to constrict and may reduce symptoms.
• Guar gum: This thickening agent may slow the emptying of the stomach after a meal, helping to relieve symptoms.
• Exercise: Getting plenty of exercise between meals—such as walking—can improve vascular tone and diminish symptoms of postprandial hypotension.

If symptoms are severe and cannot be controlled by other measures, subcutaneous injections of octreotide (a drug that behaves like the pancreatic hormone somatostatin) before a meal may help reduce the amount of blood flowing to the intestine. However, this treatment is quite expensive and can cause significant side effects.

Summary

Since “postprandial” means “after a meal,” it makes sense that postprandial hypotension refers to a dramatic blood pressure drop that occurs after someone stands up after a meal. This drop can trigger predictable symptoms like dizziness, lightheadedness, weakness, and even a loss of consciousness. The condition is still something of a mystery to doctors, but they think it could be related to the pooling of blood that occurs in the abdominal organs as food is being digested. In other words, the blood pools in one place instead of being circulated everywhere in the body, setting off a drop in blood pressure. Heeding four tips can help you keep postprandial hypotension under control.

A Word From Verywell

Postprandial hypotension can occasionally become a significant problem, especially among older adults. However, the majority of people who have this condition learn how to control it. It's never easy to make fundamental changes to the way you eat, so try making small changes a little at a time rather than a wholesale change at once.