Orthostatic intolerance (OI) is a condition that causes a change in blood pressure when going from sitting or lying down to standing. Individuals with OI cannot tolerate standing upright for long periods and their symptoms are relieved once they sit or lie down. OI is linked to problems with reduced blood flow to the brain and the body’s ability to regulate and control heart rate and blood pressure, which causes the most predominate symptom fainting known as syncope. When individuals with OI stand up they may faint or have reduced mental abilities such as memory loss, decreased ability to focus or make decisions. Lightheadedness, dizziness, vision problems, headache, fatigue, nausea, abdominal pain, sweating, and difficulty exercising are also possible symptoms of OI. There are different types of OI and OI can be a main symptom of different conditions.
Orthostatic intolerance can be diagnosed by reviewing an individual’s symptom history and determining if symptoms resolve after lying down. If symptoms occur when a person is lying down then they do not have OI. A test can be done to monitor heart rate and blood pressure while a patient goes from lying down to standing. If there is an inappropriate change in heart rate and blood pressure this is good evidence OI may be the cause. Often, these conditions tend to be misdiagnosed as either a psychiatric or anxiety related disorders, due to the nature of the symptoms.
Treatment for OI depends upon the type of OI and what type of malfunction is causing the symptoms. Individuals should avoid overheating and can try drinking water or salt water. Individuals can try tightening certain muscles or changing their body position to help counter act the changes in heart rate and blood pressure. There are some medications available to ease symptoms but they are not completely effective in all cases. For some OI can significantly interrupt daily life and reduce quality of life.
Description Last Updated: Apr 06, 2018