Low Blood Pressure, Orthostatic Hypotension, Postural Hypotension
What is Hypotension?
Hypotension literally means diminished tension or a condition of low blood pressure. A normal blood pressure reading is one that ranges form 140/90-100/60mmHg.
A consistently low systolic (top number) pressure, one below 100mmHg is often not associated with ill health and may be considered a positive medical finding.
However, drastic drops in blood pressure can also be life threatening, and an extremely low blood pressure can signal a serious condition or illness.
Orthostatic or postural hypotension occurs upon rising too rapidly from a lying or sitting position or from standing in a fixed position for an extended period of time. Conditions of shock (circulatory, neurogenic, septic, or allergic) resulting in acute peripheral circulatory failure can also account for hypotension.
Internal hemorrhaging or severe blood loss due to injury and/or trauma leading to shock can cause a disproportionate relationship between blood volume and the capacity of the circulatory system.
How is it diagnosed?
History: Individuals may report symptoms of dizziness, fainting (syncope), and blurred vision.
Physical exam: Monitoring of individual vital signs is crucial. Diagnosis is based on listening (auscultation) using a blood pressure cuff and stethoscope. Physical symptoms relating to shock include pale, cold, clammy skin, weak but rapid pulse and sometimes difficulty breathing with bluish nail beds and or lips.
Tests: While there is no specific test for hypotension, tests to determine underlying physical disorders may be necessary.
How is Hypotension treated?
Treatment may include medications to decrease the diameter of blood vessels, thereby elevating blood pressure, blood and plasma transfusions to increase blood volume, oxygen administration, and sodium bicarbonate for acidosis.
Treatment depends almost entirely on the presence of symptoms and the underlying cause(s) of low blood pressure. In some cases, a physician may prescribe medication either to raise the blood pressure or to prevent the heart from slowing down. Sometimes, an increase in salt intake may be prescribed as well as avoiding dehydration. For patients with postprandial hypotension, avoiding large meals and large amounts of carbohydrates may help regulate their blood pressure. Patients may also be advised to avoid alcohol and standing suddenly, especially after eating.
Medications that raise blood pressure by increasing sodium retention and absorption may be prescribed. Individuals with orthostatic hypotension may be prescribed fludrocortison, a medication that increases blood volume and is typically well-tolerated by patients. Other drugs that may be prescribed include ephedrine, midodrine, nonsteroidal anti-inflammatory drugs (NSAIDs) and caffeine. Patients with neurally mediated hypotension may be prescribed beta blockers. In addition, compression leg stockings may be used to improve blood return to the heart.
Sometimes treatment is not necessary because the kidneys can naturally balance low blood pressure by retaining salt and water, thereby increasing blood volume to allow the heart to work more effectively.
However, this self-regulating system is not foolproof – increasing the retention of salt and water may ultimately end up worsening the condition. People are encouraged to speak to their physicians if they have had low blood pressure readings or related symptoms.
What might complicate it?
Medications used for high blood pressure (hypertension) may result in an undesirable low pressure reading.
The condition is considered quite manageable, and outcome is favorable in most instances. Uncomplicated laryngitis usually results in full recovery within a short period.
This condition could be related to or caused by medications used to treat anxiety disorders, hypertension, or insomnia, drug and alcohol consumption on the part of the individual, a psychogenic reaction, or mental depression.
Cardiologist and internist. Internist and otolaryngologist.
Last updated 6 August 2011