Blood pressure readings reflect the pressure in the arteries when the heart is pumping and at rest. Although blood pressure is frequently measured to check for hypertension, abnormally low blood pressure may be the result of other health conditions.
Low Blood Volume
One potential cause of low blood pressure is an abnormally low blood volume, MayoClinic.com reports. This can be caused by severe dehydration, which lowers the liquid volume of the blood. Severe blood loss may also result in blood pressure being lowered.
Cardiovascular Problems
Low blood pressure may be the result of problems with the cardiovascular system. For example, many different heart problems--including heart attack, arrhythmias, slowed heart rate, heart valve disease and heart failure--can all cause hypotension, according to the National Heart Lung and Blood Institute. Some drugs that are taken to lower blood pressure, such as calcium channel blockers and beta-blockers, may also cause low blood pressure if the right dose is not taken.
Systemic Problems
Low blood pressure may be caused by shock, which can occur during severe allergic reactions, known as anaphylaxis. A decrease in blood pressure may be the result of a bacterial infection in the bloodstream. Endocrine problems, such as thyroid conditions or advanced diabetes, may also result in low blood pressure.
