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Postural Hypotension
Orthostatic hypotension, also known as postural hypotension, is a medical condition wherein a person's blood pressure drops when they are standing up ( orthostasis) or sitting down. Primary orthostatic hypotension is also often referred to as neurogenic orthostatic hypotension. The drop in blood pressure may be sudden ( vasovagal orthostatic hypotension), within 3 minutes (classic orthostatic hypotension) or gradual (delayed orthostatic hypotension). 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 (or absent) 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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellipsis (linguistics)
In linguistics, ellipsis () or an elliptical construction is the omission from a clause of one or more words that are nevertheless understood in the context of the remaining elements. There are numerous distinct types of ellipsis acknowledged in theoretical syntax. Theoretical accounts of ellipsis seek to explain its syntactic and semantic factors, the means by which the elided elements are recovered, and the status of the elided elements. Background Varieties of ellipsis have long formed a basis of linguistic theory that addresses basic questions of form–meaning correspondence: in particular, how the usual mechanisms of grasping a meaning from a form may be bypassed or supplanted via elliptical structures. In generative linguistics, the term ''ellipsis'' has been applied to a range of syntax in which a perceived interpretation is fuller than that which would be expected based solely on the presence of linguistic forms. One trait that many types and instances of ellipsis h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autonomic Neuropathy
Autonomic neuropathy (AN or AAN) is a form of polyneuropathy that affects the non-voluntary, non-sensory nervous system (i.e., the autonomic nervous system), affecting mostly the internal organs such as the bladder muscles, the cardiovascular system, the digestive tract, and the genital organs. These nerves are not under a person's conscious control and function automatically. Autonomic nerve fibers form large collections in the thorax, abdomen, and pelvis outside the spinal cord. They have connections with the spinal cord and ultimately the brain, however. Most commonly autonomic neuropathy is seen in persons with long-standing diabetes mellitus type 1 and 2. In most—but not all—cases, autonomic neuropathy occurs alongside other forms of neuropathy, such as sensory neuropathy. Autonomic neuropathy is one cause of malfunction of the autonomic nervous system (referred to as dysautonomia), but not the only one; some conditions affecting the brain or spinal cord also may cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anxiety
Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response to a present threat, whereas anxiety is the anticipation of a future one. It is often accompanied by nervous behavior such as pacing back and forth, Somatic anxiety, somatic complaints, and Rumination (psychology), rumination. Anxiety is a feeling of uneasiness and worry, usually generalized and unfocused as an overreaction to a situation that is only subjectively seen as menacing. It is often accompanied by muscular tension, restlessness, Fatigue (medical), fatigue, inability to catch one's breath, tightness in the abdominal region, nausea, and problems in concentration. Anxiety is closely related to fear, which is a response to a real or perceived immediate threat (fight-or-flight response); anxiety involves the expectation of a future t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertigo
Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspiration, or difficulties walking. It is typically worse when the head is moved. Vertigo is the most common type of dizziness. The most common disorders that result in vertigo are benign paroxysmal positional vertigo (BPPV), Ménière's disease, and vestibular neuritis. Less common causes include stroke, brain tumors, brain injury, multiple sclerosis, migraines, trauma, and uneven pressures between the middle ears. Physiologic vertigo may occur following being exposed to motion for a prolonged period such as when on a ship or simply following spinning with the eyes closed. Other causes may include toxin exposures such as to carbon monoxide, alcohol, or aspirin. Vertigo typically indicates a problem in a part of the vestibular system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blurred Vision
Blurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details. Temporary blurred vision may involve dry eyes, eye infections, alcohol poisoning, hypoglycemia, or low blood pressure. Other medical conditions may include refractive errors such as myopia, high hypermetropia, and astigmatism, amblyopia, presbyopia, pseudomyopia, diabetes, cataract, pernicious anemia, vitamin B12 deficiency, thiamine deficiency, glaucoma, retinopathy, hypervitaminosis A, migraine, sjögren's syndrome, floater, macular degeneration, and can be a sign of stroke or brain tumor. __TOC__ Causes There are many causes of blurred vision: * Refractive errors: Uncorrected refractive errors like myopia, high hypermetropia, and astigmatism will cause distance vision blurring. It is one of the leading cause of visual impairment worldwide. Unless there is no associated amblyopia, visual blur due to refractive errors can be corrected to n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falling (accident)
Falling is the action of a person or animal losing stability and ending up in a lower position, often on the ground. It is the second-leading cause of accidental death worldwide and a major cause of personal injury, especially for the old age, elderly. Falls in older adults are a major class of preventive healthcare, preventable injuries. Construction workers, electricians, miners, and house painter and decorator, painters are job (role), occupations with high rates of fall injuries. Long-term exercise appears to decrease the rate of falls in older people. About 226 million cases of significant accidental falls occurred in 2015. These resulted in 527,000 deaths. Causes and risk factors Accidents The most common cause of falls in healthy adults is accidents. It may be by slipping or tripping from stable surfaces or stairs, improper footwear, dark surroundings, uneven ground, or lack of exercise. Studies suggest that women are more prone to falling than men in all age groups. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syncope (medicine)
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. Causes range from non-serious to potentially fatal. There are three broad categories of causes: heart or blood vessel related; reflex, also known as neurally mediated; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Presyncope
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. Keeping a sense of balance requires the brain to process a variety of information received from the eyes, the nervous system, and the inner ears. If the brain is unable to process these signals, such as when the messages are contradictory, or if the sensory systems are improperly functioning, an individual may experience lightheadedness or dizziness. Lightheadedness is very similar to pre-syncope. Pre-syncope is the immediate stage before syncope (fainting), particularly in cases of temporary visual field loss (i.e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baroreceptor
Baroreceptors (or archaically, pressoreceptors) are stretch receptors that sense blood pressure. Thus, increases in the pressure of blood vessel triggers increased action potential generation rates and provides information to the central nervous system. This sensory information is used primarily in autonomic reflexes that in turn influence the heart cardiac output and vascular smooth muscle to influence vascular resistance. Baroreceptors act immediately as part of a negative feedback system called the baroreflex as soon as there is a change from the usual mean arterial blood pressure, returning the pressure toward a normal level. These reflexes help regulate short-term blood pressure. The solitary nucleus in the medulla oblongata of the brain recognizes changes in the firing rate of action potentials from the baroreceptors, and influences cardiac output and systemic vascular resistance. Baroreceptors can be divided into two categories based on the type of blood vessel in whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midodrine
Midodrine, sold under the brand names ProAmatine and Orvaten among others, is an antihypotensive medication used to treat orthostatic hypotension (low blood pressure when standing) and urinary incontinence. It is taken oral administration, by mouth. Side effects of midodrine include hypertension (high blood pressure), paresthesia, pruritus, itching, goosebumps, chills, urinary urgency, urinary retention, and urinary frequency. Midodrine is a prodrug of its active metabolite desglymidodrine. This metabolite acts as a binding selectivity, selective agonist of the alpha-1 adrenergic receptor, α1-adrenergic receptor. This in turn results in vasoconstriction and increased blood pressure. Midodrine was discovered by 1971 and was introduced for medical use in the United States in 1996. Medical uses Midodrine is indicated for the treatment of symptomatic orthostatic hypotension. It can reduce dizziness and faints by about a third, but can be limited by troublesome goose bumps, prur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fludrocortisone
Fludrocortisone, sold under the brand name Florinef among others, is a corticosteroid used to treat congenital adrenal hyperplasia, postural hypotension, and adrenal insufficiency. In adrenal insufficiency, it is generally taken together with hydrocortisone. Fludrocortisone is taken by mouth and is most commonly used in its acetate form. Common side effects of fludrocortisone include high blood pressure, swelling, heart failure, and low blood potassium. Other serious side effects can include low immune-system function, cataracts, muscle weakness, and mood changes. Whether use of fludrocortisone during pregnancy is safe for the fetus is unknown. Fludrocortisone is mostly a mineralocorticoid, but it also has glucocorticoid effects. Fludrocortisone was patented in 1953. It is on the World Health Organization's List of Essential Medicines. Medical uses Fludrocortisone has been used in the treatment of cerebral salt-wasting syndrome. It is used primarily to replace the mis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
