The history in patients with autonomic insufficiency may reveal symptoms related to orthostatic hypotension, abnormalities of sweating, or dysfunction of the GI or genitourinary tracts. Symptoms of orthostasis include dizziness or lightheadedness, feelings of presyncope, syncope, palpitations, tremulousness, weakness, confusion, or slurred speech, all worse with standing. Occasional patients complain only of difficulty walking. The symptoms of orthostasis are often worse postprandially,
after a hot bath or ingestion of alcohol, or following exercise. Sweating abnormalities may produce abnormal dryness of the skin, sometimes with excessive sweating in uninvolved regions. Other symptoms include constipation, dysphagia, early satiety, anorexia, diarrhea (particularly at night), weight loss, erectile dysfunction, ejaculatory failure, retrograde ejaculation, urinary retention, urinary urgency, recurrent urinary tract infections, and urinary or fecal incontinence.

The general physical and neurologic examinations may reveal a variety of abnormalities in patients with disorders of the autonomic nervous system. Acromegaly, dwarfism, signs of endocrine imbalance or sexual immaturity may indicate a hypothalamic abnormality. Abnormal dryness of the skin may be a sign of sudomotor failure and could occur in a localized distribution, as with a peripheral nerve injury, or be generalized, as in diffuse dysautonomia. Lack of normal moisture in the socks may indicate deficient sweating. A simple bedside test to demonstrate the distribution of abnormal skin dryness related to loss of sweating is to note the resistance to stroking of the skin with a finger or an object such as the barrel of a pen or a spoon. When a spoon is drawn over the skin, it pulls smoothly over dry (sympathectomized) skin but irregularly and unevenly over moist, perspiring skin. It is often possible to see the sweat droplets on the skin, especially on the papillary ridges of the fingers, using the +20 ophthalmoscope lens. Other cutaneous signs of autonomic dysregulation include changes in skin temperature or color, mottling, alopecia, hypertrichosis, thickening or fragility of the nails, absent piloerection, decreased hand wrinkling in water, and skin atrophy. Acral vasomotor dysregulation may lead to pallor, acrocyanosis, mottling, erythema, or livedo reticularis. Patients with dysautonomia associated with a regional pain syndrome may have allodynia and hyperalgesia in addition to the autonomic changes.

Assessment of orthostatic changes in blood pressure (BP) and heart rate (HR) are basic tests of cardiovascular autonomic function. At the bedside, BP and pulse are taken with the patient supine and after standing for variable periods, typically the BP is determined at 1, 3, and 5 minutes after standing. Tilt table testing is more precise. Normally, systolic blood pressure (SBP) on standing does not decrease by more than 20 mm Hg, and the diastolic blood pressure (DBP) by not more than 10 mm Hg. There are more stringent diagnostic criteria that permit a 30-point drop in SBP or a 15-point drop in DBP in normals. When BP measurement is done with a standard sphygmomanometer, the cuff should be kept at heart level to minimize hydrostatic influence on the measurement. When routine measurements are unrevealing, orthostatic blood pressure declines can sometimes be detected by having the patient perform 5 to 10 squats and then repeating the measurements.

The HR should not increase by more than 30 beats per minute above baseline on standing. In hypovolemia, the most common cause of orthostasis, a reflex tachycardia develops in response to the fall in standing blood pressure. When autonomic cardiovascular reflexes are impaired, the reflex tachycardia may not occur. Patients with the postural tachycardia syndrome will develop a brisk tachycardia without orthostatic hypotension (increased pulse rate more than 30 beats per minute above baseline or more than 120 beats per minute). The sustained hand grip, mental stress, and cold pressor tests all look for increases in DBP of at least 15 mm Hg or an increase in HR of >10 beats per minute in response to peripheral vasoconstriction induced respectively by isometric hand exercise, mental arithmetic, or immersion of the hand in cold water. The cold face test assesses the trigeminovagal (diving) reflex. Resting tachycardia may be a sign of parasympathetic dysfunction.

Clinical assessment of bladder function is done by looking for evidence of distension by palpation and percussion, and by checking the anal wink and bulbocavernous reflexes. The bulbocavernous and superficial anal reflexes are somatic motor reflexes; the internal anal and scrotal reflexes are autonomic reflexes. The internal anal sphincter reflex is contraction of the internal sphincter on insertion of a gloved finger into the anus. If the reflex is impaired there is decreased sphincter tone and the anus does not close immediately after withdrawal. Post void residual urine volume is determined by catheterization after voiding.