From the Guidelines

Hypotension is primarily caused by vasodilation, hypovolaemia, bradycardia, and low cardiac output 1.

Vasodilation: can be reversed by vasopressors such as phenylephrine or norepinephrine 1
Hypovolaemia: can be treated with intravascular fluid administration using crystalloid and colloid solutions or blood 1
Bradycardia: typically pharmacologically managed with anticholinergic agents such as atropine or glycopyrronium; when not responsive to these agents, epinephrine or isoprenaline might be necessary 1
Low cardiac output: due to acute or chronic myocardial dysfunction can be treated with positive inotropic agents such as dobutamine or epinephrine 1 Other factors that may contribute to hypotension include orthostatic hypotension, which is defined as a drop in systolic blood pressure of ≥20 mmHg or diastolic blood pressure of ≥10 mmHg with assumption of an upright posture 1.

Hypotension can result from several underlying physiological processes acting alone or in combination 1
Initial management involves identifying and addressing the underlying cause of hypotension 1

From the Research

The causes of hypotension, also known as low blood pressure, can be attributed to various factors. Some of the possible causes include:

Shock, which is circulatory insufficiency, inadequate oxygen delivery, and cellular hypoxia 2
Hemorrhagic shock, which is recognized as a sign of hypotension and is a validated prognostic indicator 3
Anesthesia, particularly spinal anesthesia, which can cause hypotension due to the blockade of sympathetic nerves 4
Heart failure, which can lead to orthostatic hypotension, a common comorbidity among patients with heart failure 5
Dehydration, which can cause a decrease in blood volume and lead to hypotension 2
Certain medications, such as those used to treat high blood pressure, which can cause hypotension as a side effect

Several risk factors can increase the likelihood of developing hypotension, including:

Age, with older adults being more susceptible to hypotension 3
Severity of heart failure, with more severe heart failure increasing the risk of orthostatic hypotension 5
Non-ischemic heart failure etiology, which can increase the risk of orthostatic hypotension 5
Prolonged bed rest, which can cause orthostatic hypotension due to decreased blood volume and cardiac output 5
Hypertension, which can increase the risk of orthostatic hypotension 5
Polypharmacy, which can increase the risk of orthostatic hypotension due to the interactions between multiple medications 5

The symptoms of hypotension can vary depending on the severity and cause of the condition. Some common symptoms include:

Dizziness or lightheadedness, which can occur when standing up or changing positions 5
Palpitations, which can occur due to the heart beating faster to compensate for the low blood pressure 5
Nausea or vomiting, which can occur due to the decreased blood flow to the brain and other organs 4
Fatigue or weakness, which can occur due to the decreased blood flow to the muscles and other tissues 2
Shortness of breath, which can occur due to the decreased blood flow to the lungs 2