Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when standing up or sitting down. Primary orthostatic hypotension is also often referred to as neurogenic orthostatic hypotension. The drop in blood pressure may be sudden, within 3 minutes or gradual. It is defined as a fall in systolic blood pressure of at least 20 mmHg or diastolic blood pressure of at least 10 mmHg after 3 minutes of standing. It occurs predominantly by delayed constriction of the lower body blood vessels, which is normally required to maintain adequate blood pressure when changing the position to standing. As a result, blood pools in the blood vessels of the legs for a longer period, and less is returned to the heart, thereby leading to a reduced cardiac output and inadequate blood flow to the brain.
Polyuria is excessive or an abnormally large production or passage of urine. Increased production and passage of urine may also be termed as diuresis. Polyuria often appears in conjunction with polydipsia, though it is possible to have one without the other, and the latter may be a cause or an effect. Primary polydipsia may lead to polyuria. Polyuria is usually viewed as a symptom or sign of another disorder, but it can be classed as a disorder, at least when its underlying causes are not clear.
Dysautonomia, autonomic failure, or autonomic dysfunction is a condition in which the autonomic nervous system (ANS) does not work properly. This may affect the functioning of the heart, bladder, intestines, sweat glands, pupils, and blood vessels. Dysautonomia has many causes, not all of which may be classified as neuropathic. A number of conditions can feature dysautonomia, such as Parkinson's disease, multiple system atrophy, dementia with Lewy bodies, Ehlers–Danlos syndromes, autoimmune autonomic ganglionopathy and autonomic neuropathy, HIV/AIDS, mitochondrial cytopathy, pure autonomic failure, autism, and postural orthostatic tachycardia syndrome.
Flushing is to become markedly red in the face and often other areas of the skin, from various physiological conditions. Flushing is generally distinguished from blushing, since blushing is psychosomatic, milder, generally restricted to the face, cheeks or ears, and generally assumed to reflect emotional stress, such as embarrassment, anger, or romantic stimulation. Flushing is also a cardinal symptom of carcinoid syndrome—the syndrome that results from hormones being secreted into systemic circulation.
Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart.
Hypovolemia, also known as volume depletion or volume contraction, is a state of abnormally low extracellular fluid in the body. This may be due to either a loss of both salt and water or a decrease in blood volume. Hypovolemia refers to the loss of extracellular fluid and should not be confused with dehydration.
Familial dysautonomia (FD), also known as Riley-Day syndrome, is a rare, progressive, recessive genetic disorder of the autonomic nervous system that affects the development and survival of sensory, sympathetic, and some parasympathetic neurons in the autonomic and sensory nervous system.
Orthostatic intolerance (OI) is the development of symptoms when standing upright that are relieved when reclining. There are many types of orthostatic intolerance. OI can be a subcategory of dysautonomia, a disorder of the autonomic nervous system occurring when an individual stands up. Some animal species with orthostatic hypotension have evolved to cope with orthostatic disturbances.
Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by an abnormally large increase in heart rate upon sitting up or standing. POTS is a disorder of the autonomic nervous system that can lead the individual to experience a variety of symptoms. Symptoms may include lightheadedness, brain fog, blurred vision, weakness, fatigue, headaches, heart palpitations, exercise intolerance, nausea, diminished concentration, tremulousness (shaking), syncope (fainting), coldness or pain in the extremities, Numbness or tingling in the extremities, chest pain and shortness of breath. Other conditions associated with POTS include migraine headaches, Ehlers–Danlos syndrome, asthma, autoimmune disease, vasovagal syncope and mast cell activation syndrome. POTS symptoms may be treated with lifestyle changes such as increasing fluid, electrolyte, and salt intake, wearing compression stockings, gentler and slow postural changes, avoiding prolonged bedrest, medication, and physical therapy.
Exercise intolerance is a condition of inability or decreased ability to perform physical exercise at the normally expected level or duration for people of that age, size, sex, and muscle mass. It also includes experiences of unusually severe post-exercise pain, fatigue, nausea, vomiting or other negative effects. Exercise intolerance is not a disease or syndrome in and of itself, but can result from various disorders.
Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel as though their head is weightless. The individual may also feel as though the room is "spinning" or moving (vertigo). Most causes of lightheadedness are not serious and either cure themselves quickly or are easily treated.
A tilt table test (TTT), occasionally called upright tilt testing (UTT), is a medical procedure often used to diagnose dysautonomia or syncope. Patients with symptoms of dizziness or lightheadedness, with or without a loss of consciousness (fainting), suspected to be associated with a drop in blood pressure or positional tachycardia are good candidates for this test.
Da Costa's syndrome, also known as soldier's heart among other names, was a syndrome or a set of symptoms similar to those of heart disease. These include fatigue upon exertion, shortness of breath, palpitations, sweating, chest pain, and sometimes orthostatic intolerance. It was originally thought to be a cardiac condition, and treated with a predecessor to modern cardiac drugs. In modern times, it is believed to represent several unrelated disorders, some of which have a known medical basis.
Acrocyanosis is persistent blue or cyanotic discoloration of the extremities, most commonly occurring in the hands, although it also occurs in the feet and distal parts of face. Although described over 100 years ago and not uncommon in practice, the nature of this phenomenon is still uncertain. The very term "acrocyanosis" is often applied inappropriately in cases when blue discoloration of the hands, feet, or parts of the face is noted. The principal (primary) form of acrocyanosis is that of a benign cosmetic condition, sometimes caused by a relatively benign neurohormonal disorder. Regardless of its cause, the benign form typically does not require medical treatment. A medical emergency would ensue if the extremities experience prolonged periods of exposure to the cold, particularly in children and patients with poor general health. However, frostbite differs from acrocyanosis because pain often accompanies the former condition, while the latter is very rarely associated with pain. There are also a number of other conditions that affect hands, feet, and parts of the face with associated skin color changes that need to be differentiated from acrocyanosis: Raynaud phenomenon, pernio, acrorygosis, erythromelalgia, and blue finger syndrome. The diagnosis may be challenging in some cases, especially when these syndromes co-exist.
Hypohidrosis is a disorder in which a person exhibits diminished sweating in response to appropriate stimuli. In contrast with hyperhidrosis, which is a socially troubling yet often benign condition, the consequences of untreated hypohidrosis include hyperthermia, heat stroke and death. An extreme case of hypohidrosis in which there is a complete absence of sweating and the skin is dry is termed anhidrosis.
Syncope, commonly known as fainting or passing out, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, typically from low blood pressure. There are sometimes symptoms before the loss of consciousness such as lightheadedness, sweating, pale skin, blurred vision, nausea, vomiting, or feeling warm. Syncope may also be associated with a short episode of muscle twitching. Psychiatric causes can also be determined when a patient experiences fear, anxiety, or panic; particularly before a stressful event, usually medical in nature. When consciousness and muscle strength are not completely lost, it is called presyncope. It is recommended that presyncope be treated the same as syncope.
Orthostatic headache is a medical condition in which a person develops a headache while vertical and the headache is relieved when horizontal. Previously it was often misdiagnosed as different primary headache disorders such as migraine or tension headaches. Increasing awareness of the symptom and its causes has prevented delayed or missed diagnosis.
Dopamine beta (β)-hydroxylase deficiency is a human medical condition involving inadequate dopamine beta-hydroxylase. It is characterized by increased amounts of serum dopamine and the absence of norepinephrine (NE) and epinephrine.
Orthostatic hypertension is a medical condition consisting of a sudden and abrupt increase in blood pressure (BP) when a person stands up. Orthostatic hypertension is diagnosed by a rise in systolic BP of 20 mmHg or more when standing. Orthostatic diastolic hypertension is a condition in which the diastolic BP raises to 98 mmHg or over in response to standing, but this definition currently lacks clear medical consensus, so is subject to change. Orthostatic hypertension involving the systolic BP is known as systolic orthostatic hypertension.
Autoimmune autonomic ganglionopathy is a type of immune-mediated autonomic failure that is associated with antibodies against the ganglionic nicotinic acetylcholine receptor present in sympathetic, parasympathetic, and enteric ganglia. Typical symptoms include gastrointestinal dysmotility, orthostatic hypotension, and tonic pupils. Many cases have a sudden onset, but others worsen over time, resembling degenerative forms of autonomic dysfunction. For milder cases, supportive treatment is used to manage symptoms. Plasma exchange, intravenous immunoglobulin, corticosteroids, or immunosuppression have been used successfully to treat more severe cases.
