A feeling of dizziness or nausea when changing body position is known as orthostatic hypotension or postural hypotension. The condition is caused by sudden drop in blood pressure that causes a person to experience short-term lightheadedness. Although not usually harmful on its own, chronic orthostatic hypotension can be a sign of a more serious condition and can require medical attention in severe instances.
When seated or lying down, blood tends to collect in the legs, feet, and lower regions of the body, draining the upper body of its typical level of blood flow. If a person stands suddenly, the loss of blood in the upper body may become apparent, causing lightheadedness, dizziness, or a feeling of faintness. In more serious cases, this can lead to blackouts, vomiting, or blurred vision.
The reason orthostatic hypotension is not always experienced is that the body attempts to quickly protect itself from the lack of blood by employing vasoconstriction. This natural process quickly circulates blood through the body, returning blood pressure to normal and preventing any symptoms of orthostatic hypotension. If a secondary factor, such as an illness or blood problem, slows the return of blood to the upper body, symptoms may present in mild or serious forms.
Causes of orthostatic hypotension are quite varied. Lifestyle problems such as inadequate nutrition, dehydration, or heat stroke can lead to a temporary drop in blood pressure and make dizziness when standing up a problem. Older people are also more likely to experience the condition as their circulation system is naturally somewhat slowed.
Certain medications can also lead to orthostatic hypotension. It can be a common side effect of medications for high blood pressure, especially if the medication is taken in large doses. Many medical conditions such as diabetes, heart problems, and Parkinson's disease have been shown to decrease blood pressure and make orthostatic hypotension more common. Women who have recently given birth and people undergoing bed rest are also considered somewhat more likely to experience symptoms. It can also be a common problem for people suffering from eating disorders such as anorexia and bulimia.
If dizziness or nausea upon standing is a constant or frequent occurrence, a medical professional should be contacted. While relatively harmless by itself, orthostatic hypotension can indicate a on patients with the condition often include bloodworm, stress tests, and heart rate tests. If blood pressure is determined to be too low for normal functions, some prescription medications may be given to treat the condition.