Orthostatic hypotension is a condition that occurs when baroreceptors located in the aorta and carotid arteries fail to detect and rectify a drop in blood pressure when standing up from a sitting or lying down position.
How is orthostatic hypotension diagnosed?
The best way to diagnose orthostatic hypotension is to evaluate underlying contributing factors.
Initially, a medical history is taken, noting any pre-existing health conditions and prescribed medications. Following this, the patient’s blood pressure is measured while sitting, standing and lying down. A significant drop in blood pressure between sitting and standing may indicate orthostatic hypotension.
Patients with suspected orthostatic hypotension may also undergo a physical examination. The presence of specific symptoms may indicate medical conditions which could underlie the hypotension. Some of these include:
- stroke-related symptoms (unilateral paresis, facial drop, and speech problem)
- congestive heart failure or myocardial infarction-related symptoms (cardiac murmur)
- Parkinson’s disease-related symptoms (muscle stiffness, impaired locomotion, and loss of facial expression)
- dehydration-related symptoms (confusion, upper body weakness, dry tongue, speech problem, and sunken eyes)
- pure autonomic failure-related symptoms (lack of sexual drive, impotence, and lack of voluntary control over urination/defecation)
- congestive heart failure or venous insufficiency-related symptoms (dependent edema in lower extremities and stasis dermatitis)
in addition, the physician may carry out blood tests to check the patient’s blood glucose level (in case of diabetes), red blood cell count (which may indicate anemia) and/or adrenal hormone levels to determine the cause of this drop in blood pressure,.
An electrocardiogram (ECG) may also be useful in ruling out any cardiovascular diseases. In this method, electrodes are placed on the chest, legs, and arms, and are used to detect electrical signals within the heart. This produces a graph of the heart’s rhythm. For patients who do not exhibit any changes during this procedure but are suspected to have a heart condition, a Holter ECG monitoring system may be used to measure changes in the heart rhythm over time.
To confirm a heart condition, the physician may carry out an echocardiogram. In this procedure, a transducer is placed on the chest, and sound waves are processed electronically to generate video images of the heart. This footage is then used to determine whether the patient has any structural defects of the heart.
If any structural or functional abnormality is detected, the clinician may then ask for a stress test. Here echo/electrocardiographic examinations of the heart are carried out while exercising, such as walking on a treadmill.
Since orthostatic hypotension occurs due to a change in body position, the clinician sometimes recommends a ‘Tilt table’ test. This test is particularly performed in patients who are prone to fainting.
In this method, patients lie down on a table that inclines to elevate the upper part of the body, thus simulating the movement from a supine to a standing position. The blood pressure is measured several times during tilting of the table.
In addition, the sympathetic/parasympathetic regulation of blood pressure is analyzed by the Valsalva maneuver. The heart rate and blood pressure are monitored while the patient is breathing deeply against resistance several times.
How is orthostatic hypotension treated?
Mild or occasional orthostatic hypotension does not need any special medical attention; the best way to treat this condition is to sit or lie down immediately after feeling dizzy. However, chronic orthostatic hypotension can lead to serious consequences, and requires immediate medical attention.
In most cases, chronic orthostatic hypotension can be prevented by simple lifestyle changes, such as:
- Increasing fluid intake
- Reducing alcohol consumption
- Avoiding prolonged stays in a hot environment
- Elevating the position of the head while sleeping
- Avoid keeping the legs crossed while sitting
- Standing up slowly and avoid standing for a long time
- Avoiding a carbohydrate-rich diet
One of the best non-pharmacological ways of treating orthostatic hypotension is to perform isometric exercises, such as squeezing a rubber ball before standing up. This helps elevate the blood pressure. In addition, compression stockings/abdominal binders can be used to reduce pooling of blood in the legs/abdomen and prevent a blood pressure fall.
Orthostatic hypotension symptoms related to specific medicines are generally treated by changing the medicine or altering the dose. In addition, clinicians sometimes recommend salt supplementation to increase the sodium level in urine.
Patients who are nonresponsive to non-pharmacological treatments are generally prescribed medications such as corticosteroids, selective α1-adrenergic agonists ( which increase systolic blood pressure), and cholinesterase inhibitors (which improve transmission through acetylcholine-mediated neurons of the autonomic nervous system).