Sudden low blood pressure, or orthostatic hypotension, may be caused by a sudden change in posture. Standing up suddenly from a lying or sitting position is the most common cause of this condition. Individuals are said to have low blood pressure when their reading appears below 90 systolic and 60 diastolic, according to WebMD.
Sudden low blood pressure is sometimes referred to as postural hypotension, notes Mayo Clinic. The most common symptoms for this condition include dizziness or lightheadedness, general body weakness, blurry vision, fainting, nausea and confusion.
In most cases, orthostatic hypotension results from blood pooling at the legs due to gravitational pull. This means blood does not circulate fast enough to reach the brain in a sufficient quantity. After a short while, the body's circulation normalizes, which is why the condition only lasts a few moments. Diagnosis for this condition is commonly done by taking blood tests, stress tests, examining the patient's history and monitoring his blood pressure.
One of the issues that may lead to this condition is dehydration. To deal with this, drink plenty of fluids. Heart problems, endocrine complications and nervous system disorders are other factors that may lead to sudden low blood pressure. Doctors usually treat underlying factors to manage this condition.