Dizziness: An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness.Vertigo: An illusion of movement, either of the external world revolving around the individual or of the individual revolving in space. Vertigo may be associated with disorders of the inner ear (EAR, INNER); VESTIBULAR NERVE; BRAINSTEM; or CEREBRAL CORTEX. Lesions in the TEMPORAL LOBE and PARIETAL LOBE may be associated with FOCAL SEIZURES that may feature vertigo as an ictal manifestation. (From Adams et al., Principles of Neurology, 6th ed, pp300-1)Vestibular Diseases: Pathological processes of the VESTIBULAR LABYRINTH which contains part of the balancing apparatus. Patients with vestibular diseases show instability and are at risk of frequent falls.Vestibular Function Tests: A number of tests used to determine if the brain or balance portion of the inner ear are causing dizziness.Vestibular Neuronitis: Idiopathic inflammation of the VESTIBULAR NERVE, characterized clinically by the acute or subacute onset of VERTIGO; NAUSEA; and imbalance. The COCHLEAR NERVE is typically spared and HEARING LOSS and TINNITUS do not usually occur. Symptoms usually resolve over a period of days to weeks. (Adams et al., Principles of Neurology, 6th ed, p304)Meniere Disease: A disease of the inner ear (LABYRINTH) that is characterized by fluctuating SENSORINEURAL HEARING LOSS; TINNITUS; episodic VERTIGO; and aural fullness. It is the most common form of endolymphatic hydrops.Nystagmus, Pathologic: Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)Headache: The symptom of PAIN in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of HEADACHE DISORDERS.Whiplash Injuries: Hyperextension injury to the neck, often the result of being struck from behind by a fast-moving vehicle, in an automobile accident. (From Segen, The Dictionary of Modern Medicine, 1992)Postural Balance: A POSTURE in which an ideal body mass distribution is achieved. Postural balance provides the body carriage stability and conditions for normal functions in stationary position or in movement, such as sitting, standing, or walking.Nystagmus, Physiologic: Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair.Sensation Disorders: Disorders of the special senses (i.e., VISION; HEARING; TASTE; and SMELL) or somatosensory system (i.e., afferent components of the PERIPHERAL NERVOUS SYSTEM).Syncope: A transient loss of consciousness and postural tone caused by diminished blood flow to the brain (i.e., BRAIN ISCHEMIA). Presyncope refers to the sensation of lightheadedness and loss of strength that precedes a syncopal event or accompanies an incomplete syncope. (From Adams et al., Principles of Neurology, 6th ed, pp367-9)Labyrinth Diseases: Pathological processes of the inner ear (LABYRINTH) which contains the essential apparatus of hearing (COCHLEA) and balance (SEMICIRCULAR CANALS).Diagnostic Techniques, Otological: Methods and procedures for the diagnosis of diseases of the ear or of hearing disorders or demonstration of hearing acuity or loss.Labyrinthine Fluids: Fluids found within the osseous labyrinth (PERILYMPH) and the membranous labyrinth (ENDOLYMPH) of the inner ear. (From Gray's Anatomy, 30th American ed, p1328, 1332)Hypotension, Orthostatic: A significant drop in BLOOD PRESSURE after assuming a standing position. Orthostatic hypotension is a finding, and defined as a 20-mm Hg decrease in systolic pressure or a 10-mm Hg decrease in diastolic pressure 3 minutes after the person has risen from supine to standing. Symptoms generally include DIZZINESS, blurred vision, and SYNCOPE.Motion Sickness: Disorder caused by motion, as sea sickness, train sickness, car sickness, air sickness, or SPACE MOTION SICKNESS. It may include nausea, vomiting and dizziness.Otorhinolaryngologic Diseases: Pathological processes of the ear, the nose, and the throat, also known as the ENT diseases.Caloric Tests: Elicitation of a rotatory nystagmus by stimulating the semicircular canals with water or air which is above or below body temperature. In warm caloric stimulation a rotatory nystagmus is developed toward the side of the stimulated ear; in cold, away from the stimulated side. Absence of nystagmus indicates the labyrinth is not functioning.Nausea: An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses.Accidental Falls: Falls due to slipping or tripping which may result in injury.Vestibule, Labyrinth: An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.Abdominal Pain: Sensation of discomfort, distress, or agony in the abdominal region.Abdomen, Acute: A clinical syndrome with acute abdominal pain that is severe, localized, and rapid in onset. Acute abdomen may be caused by a variety of disorders, injuries, or diseases.Rupture, Spontaneous: Tear or break of an organ, vessel or other soft part of the body, occurring in the absence of external force.Education, Medical: Use for general articles concerning medical education.Pain: An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.Menopause: The last menstrual period. Permanent cessation of menses (MENSTRUATION) is usually defined after 6 to 12 months of AMENORRHEA in a woman over 45 years of age. In the United States, menopause generally occurs in women between 48 and 55 years of age.Menopause, Premature: The premature cessation of menses (MENSTRUATION) when the last menstrual period occurs in a woman under the age of 40. It is due to the depletion of OVARIAN FOLLICLES. Premature MENOPAUSE can be caused by diseases; OVARIECTOMY; RADIATION; chemicals; and chromosomal abnormalities.Medical Waste: Blood, mucus, tissue removed at surgery or autopsy, soiled surgical dressings, and other materials requiring special disposal procedures.Anoxia: Relatively complete absence of oxygen in one or more tissues.Cell Hypoxia: A condition of decreased oxygen content at the cellular level.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Hypoxia-Inducible Factor 1, alpha Subunit: Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.Neurology: A medical specialty concerned with the study of the structures, functions, and diseases of the nervous system.Headache Disorders: Various conditions with the symptom of HEADACHE. Headache disorders are classified into major groups, such as PRIMARY HEADACHE DISORDERS (based on characteristics of their headache symptoms) and SECONDARY HEADACHE DISORDERS (based on their etiologies). (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)Tension-Type Headache: A common primary headache disorder, characterized by a dull, non-pulsatile, diffuse, band-like (or vice-like) PAIN of mild to moderate intensity in the HEAD; SCALP; or NECK. The subtypes are classified by frequency and severity of symptoms. There is no clear cause even though it has been associated with MUSCLE CONTRACTION and stress. (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)Cluster Headache: A primary headache disorder that is characterized by severe, strictly unilateral PAIN which is orbital, supraorbital, temporal or in any combination of these sites, lasting 15-180 min. occurring 1 to 8 times a day. The attacks are associated with one or more of the following, all of which are ipsilateral: conjunctival injection, lacrimation, nasal congestion, rhinorrhea, facial SWEATING, eyelid EDEMA, and miosis. (International Classification of Headache Disorders, 2nd ed. Cephalalgia 2004: suppl 1)Vascular Headaches: Secondary headache disorders attributed to a variety of cranial or cervical vascular disorders, such as BRAIN ISCHEMIA; INTRACRANIAL HEMORRHAGES; and CENTRAL NERVOUS SYSTEM VASCULAR MALFORMATIONS.Terminology as Topic: The terms, expressions, designations, or symbols used in a particular science, discipline, or specialized subject area.Dictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.Crowdsourcing: Social media model for enabling public involvement and recruitment in participation. Use of social media to collect feedback and recruit volunteer subjects.Social Sciences: Disciplines concerned with the interrelationships of individuals in a social environment including social organizations and institutions. Includes Sociology and Anthropology.Emergency Medicine: The branch of medicine concerned with the evaluation and initial treatment of urgent and emergent medical problems, such as those caused by accidents, trauma, sudden illness, poisoning, or disasters. Emergency medical care can be provided at the hospital or at sites outside the medical facility.Certification: Compliance with a set of standards defined by non-governmental organizations. Certification is applied for by individuals on a voluntary basis and represents a professional status when achieved, e.g., certification for a medical specialty.Emergency Service, Hospital: Hospital department responsible for the administration and provision of immediate medical or surgical care to the emergency patient.Specialty Boards: Organizations which certify physicians and dentists as specialists in various fields of medical and dental practice.Physicians: Individuals licensed to practice medicine.Bacteria: One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Bacopa: A plant genus of the family Plantaginaceae. Members contain bacopaside, bacopasaponins and other dammarane type jujubogenins.Central Nervous System Diseases: Diseases of any component of the brain (including the cerebral hemispheres, diencephalon, brain stem, and cerebellum) or the spinal cord.Brain Concussion: A nonspecific term used to describe transient alterations or loss of consciousness following closed head injuries. The duration of UNCONSCIOUSNESS generally lasts a few seconds, but may persist for several hours. Concussions may be classified as mild, intermediate, and severe. Prolonged periods of unconsciousness (often defined as greater than 6 hours in duration) may be referred to as post-traumatic coma (COMA, POST-HEAD INJURY). (From Rowland, Merritt's Textbook of Neurology, 9th ed, p418)Triethyltin Compounds: Organic compounds composed of tin and three ethyl groups. Affect mitochondrial metabolism and inhibit oxidative phosphorylation by acting directly on the energy conserving processes.