How Does Sleep Apnea Affect Blood Pressure?
Normal breathing is a result of changes in the interthoracic pressures, or air pressure in the chest versus the pressure in the atmosphere. These alterations allow air to enter and exit the lungs through an open airway. If the airway should become obstructed to any degree, the amount of pressure needed to draw air though the airway is increased. Chest pressures exceeding -120 mm Hg may be reached. Over the course of time, these pressures can lead to pulmonary hypertension.
Sleep-related breathing disorders also affect systemic blood pressure. Systemically, the sleeping blood pressures of sleep disorder patients have been documented as high as 230/180. Over time, these pressures become a chronic condition, whether the patient is sleeping or not.
The connection between blood pressure issues and sleep disorders often goes undetected. Hypertensive patients are usually seen in their physician's office and treated for their symptom, without evaluation of the possible cause.
Should every hypertensive patient seen in the office be tested for sleep apnea? Definitely not. Such testing would overburden sleep disorders laboratories, and prove a fruitless expense in many cases.
But the evaluation of all hypertensive patients should include a very thorough history and physical.