There are several signs and symptoms that may lead a physician to recommend ambulatory blood pressure monitoring (ABPM) for a patient. These include:

• Borderline high blood pressure (hypertension) combined with clinical signs of organ damage, such as abnormal kidney function or left ventricular hypertrophy. In these patients, ABPM may reveal elevations in blood pressure during periods of activity or mental stress (at home or in the workplace). Because these triggers generally occur outside the physician’s office, the extent of the patient’s high blood pressure  may not have been recognized when the blood pressure reading was obtained during a medical visit. ABPM can therefore help the physician to diagnose high blood pressure in these patients.
  
  
• Resistant high blood pressure with no signs of organ damage. This is a condition in which a combination of blood pressure medications (antihypertensives) has failed to control a patient’s high blood pressure (as measured in a physician’s office). This condition could be related to the timing of the test in relation to when the medication was taken. Stress-elevated blood pressure readings also can be due to the stress of an office visit or other factors. ABPM is generally recommended if a patient’s blood pressure when measured at home indicates that the condition is responding to the medication, but these results are not seen at a physician’s office. The ABPM profile can help a physician determine if a patient’s high blood pressure is truly resistant to medication or simply appears that way because of other causes.
  
  
• Episodic high blood pressure. Blood pressure readings that alternate between high and normal may be a sign of pheochromocytoma (a tumor that usually occurs in the adrenal gland) or an anxiety disorder. The results of ABPM can be matched with a patient’s log to help diagnose these and other conditions.
  
  
• Symptoms of low blood pressure (hypotension) occurring in patients taking medications to lower blood pressure. Temporary episodes of low blood pressure in these patients may indicate the need to change their medications or dosages. Without APBM, this condition is difficult to diagnosis and correct.
  
  
• Autonomic dysfunction. A person’s autonomic nervous system controls involuntary body systems, such as heart rate, breathing and sweating. Patients with disorders of the autonomic nervous system will have a different ABPM profile than healthy patients. Signs of autonomic dysfunction that may be determined by ABPM include:
  
  
• Low blood pressure during waking hours
  
  
• High blood pressure during sleep
  
  
• Episodes of low blood pressure during the day, especially when rising from a seated or lying position (orthostatic hypotension)
  
  
• Abrupt lowering of blood pressure after meals
  
  
• Little or no variations of heart rate occurring along with the episodes of lower blood pressure
  
  
• Carotid sinus syncope and pacemaker syndrome are two conditions more easily diagnosed with a combination of ABPM and a Holter monitor or other type of continuous electrocardiogram (EKG). Carotid sinus syncope is a condition in which fainting occurs due to overactivity of the carotid sinus (a section of the carotid artery in the neck). It may be caused by pressure on the carotid artery. Pacemaker syndrome can involve dizziness, fatigue and possibly fainting. It occurs when an artificial pacemaker is no longer synchronized with the patient's own heart rhythm. As a result, the heart attempts to pump blood through a closed valve.

• White coat hypertension or office hypertension. This is a condition in which a patient’s blood pressure is elevated during physician office visits, but not in other situations. It may persist for months, even years, despite the patient’s becoming more familiar with the particular office and healthcare professionals. Curiously, other locations of recurrent stress (such as the workplace) do not seem to produce elevated blood pressure levels in patients with this condition.
  
  
• Angina pain, shortness of breath or pulmonary congestion that occurs primarily overnight. An increase in blood pressure occurring immediately before these episodes may indicate a higher risk of a cardiovascular event. EKG readings are often taken in conjunction with ABPM when assessing these patients.

In addition, research has indicated that ABPM may be a better predictor of first heart attacks in patients with high blood pressure than more traditional methods of obtaining blood pressure measurements.