There are also syndromes that can cause hypotension in patients including orthostatic hypotension, vasovagal syncope, and other rarer conditions.For many people, excessively low blood pressure can cause dizziness and fainting or indicate serious heart, endocrine or neurological disorders.For some people who exercise and are in top physical condition, low blood pressure could be normal. A single session of exercise can induce hypotension and water-based exercise can induce a hypotensive response.Treatment of hypotension may include the use of intravenous fluids or vasopressors. When using vasopressors, trying to achieve a mean arterial pressure (MAP) of greater than 70 mmHg does not appear to result in better outcomes than trying to achieve a MAP of greater than 65 mmHg in adults. Signs and symptoms
The primary symptoms of hypotension are lightheadedness or dizziness.If the blood pressure is sufficiently low, fainting (syncope) may occur.Low blood pressure is sometimes associated with certain symptoms, many of which are related to causes rather than effects of hypotension:

Causes
Low blood pressure can be caused by low blood volume, hormonal changes, widening of blood vessels, medicine side effects, severe dehydration, anemia, vitamin B12 deficiency, anaphylaxis, heart problems or endocrine problems.Reduced blood volume, hypovolemia, is the most common cause of hypotension. This can result from hemorrhage; insufficient fluid intake, as in starvation; or excessive fluid losses from diarrhea or vomiting. Hypovolemia can be induced by excessive use of diuretics.
Prognosis is therefore largely dependent on the presence or absence of cardiac disease, as well as the type and severity of the disease (if disease is present). Most notably, Noonan syndrome with hypertrophic cardiomyopathy is associated with increased mortality. History
Jacqueline Noonan was practicing as a pediatric cardiologist at the University of Iowa when she noticed that children with a rare type of heart defect, valvular pulmonary stenosis, often had a characteristic physical appearance, with short stature, webbed neck, wide spaced eyes, and low-set ears. Both boys and girls were affected. These characteristics were sometimes seen running in families but were not associated with gross chromosomal abnormalities. She studied 833 people with Noonan syndrome at the congenital heart disease clinic, looking for other congenital abnormalities, and, in 1963, presented a paper: "Associated non-cardiac malformations in children with congenital heart disease". This described 9 children who in addition to congenital heart disease had characteristic facial features, chest deformities and short stature. Dr. John Opitz, a former student of Dr. Noonans, first began to call the condition "Noonan syndrome" when he saw children who looked like those whom Dr. Noonan had described. Dr. Noonan produced a paper titled "Hypertelorism with Turner Phenotype" in 1968 where she studied 19 patients who displayed symptoms indicative of Noonans Syndrome. In 1971, at the Symposium of Cardiovascular defects, the name Noonan syndrome became officially recognized. References


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