There are two parts or two separate numbers referred to as blood pressure: systolic/diastolic. If the blood pressure is 73/43 (73 over 43), it means that the systolic pressure is 73 and the diastolic pressure is 43.
73/43 blood pressure can also be read as 73/43 mm Hg, or 73/43 millimeters of mercury. The 73 mm Hg Systolic refers to the pressure in the arteries when the heart beats, and the 43 mm Hg Diastolic is the pressure in the arteries between heartbeats.
Readings below 80/60 indicate very low blood pressure or Severe Hypotension. You may have very low blood pressure but feel fine. It depends on the person.
However, very low blood pressure could also have an underlying cause and indicate a serious heart problem or infection. In some instances severe hypotension can result in shock, causing confusion, clammy skin and rapid shallow breathing.
Very low blood pressure can also be caused by an endocrine problem, pregnancy and dehydration. Certain medications and nutritional deficiencies can also reduce your blood pressure.