Circulatory system or cardiovascular system is composed of the heart, blood vessels and blood. The heart plays the major role by pumping blood rich in oxygen and vital nutrients through the blood vessels to the cells and tissues in the body. The blood exerts the pressure on the walls of the blood vessels and that is the blood pressure. The normal blood pressure is considered to be 120/80 mm Hg.
Systolic blood pressure
The upper number in a blood reading represents the systolic blood pressure and it is the pressure that the blood makes on the walls of the blood vessels when the heart beats. The lower number represents the blood pressure when the heart is relaxed. When the blood pressure is higher than normal, it is called hypertension or high blood pressure. On the other side, when it is lower than normal, it is called low blood pressure of hypotension.
Sometimes, it happens that the systolic blood pressure is higher or lower than normal, while the corresponding diastolic blood pressure remains normal. It is called, respectively, isolated systolic hypertension or hypotension. The same thing can happen with diastolic blood pressure.
Low systolic blood pressure
When the systolic blood pressure is ranged between 90 and 119 mm Hg, it is normal. However, when it is lower than 90 mm Hg, it is considered as low systolic blood pressure. If the systolic blood pressure is low, while the diastolic pressure is normal, it is called systolic hypotension. In many cases, low systolic blood pressure indicates that the heart is not capable to pump sufficient amount of blood.
Causes of low systolic blood pressure
There are many factors that may be responsible for the occurrence of low systolic blood pressure. When a person loses blood due to some serious head injury, it can lead to systolic hypotension. Furthermore, heart disease or any acute disorder that causes damage of the heart or blood loss can lead to the appearance of systolic hypertension. Low systolic blood pressure may also be caused by overdose of certain medicines that are used for controlling of the blood pressure, as well as by dehydration of the body.
The most common warning signs of the low systolic blood pressure are dizziness, weakness and tiredness. People who suffer from low systolic blood pressure may also experience fainting, difficulty while breathing, such as shortness of breath, and pain that occur in the chest. Sometimes, systolic hypotension may lead to the shock and organ failure.