Vestibular rehabilitation (VR), also known as vestibular rehabilitation therapy (VRT), is a specialized form of physical therapy used to treat vestibular disorders or symptoms, characterized by dizziness, vertigo, and trouble with balance, posture, and vision. These primary symptoms can result in secondary symptoms such as nausea, fatigue, and lack of concentration. All symptoms of vestibular dysfunction can significantly decrease quality of life, introducing mental-emotional issues such as anxiety and depression, and greatly impair an individual, causing them to become more sedentary. Decreased mobility results in weaker muscles, less flexible joints, and worsened stamina, as well as decreased social and occupational activity. Vestibular rehabilitation therapy can be used in conjunction with cognitive behavioral therapy in order to reduce anxiety and depression resulting from an individual's change in lifestyle. Vestibular rehabilitation (VR), also known as vestibular rehabilitation therapy (VRT), is a specialized form of physical therapy used to treat vestibular disorders or symptoms, characterized by dizziness, vertigo, and trouble with balance, posture, and vision. These primary symptoms can result in secondary symptoms such as nausea, fatigue, and lack of concentration. All symptoms of vestibular dysfunction can significantly decrease quality of life, introducing mental-emotional issues such as anxiety and depression, and greatly impair an individual, causing them to become more sedentary. Decreased mobility results in weaker muscles, less flexible joints, and worsened stamina, as well as decreased social and occupational activity. Vestibular rehabilitation therapy can be used in conjunction with cognitive behavioral therapy in order to reduce anxiety and depression resulting from an individual's change in lifestyle. The term 'vestibular' refers to the inner ear system with its fluid-filled canals that allow for balance and spatial orientation. Some common vestibular disorders include vestibular neuritis, Ménière's disease, and nerve compression. Vestibular dysfunction can exist unilaterally, affecting only one side of the body, or bilaterally, affecting both sides. Vestibular damage is often irreparable and symptoms are persistent. Although the body naturally compensates for vestibular dysfunction (as it does for the dysfunction or deficiency of any sense), vestibular rehabilitation furthers the compensation process to decrease both primary and secondary symptoms. In cases of chronic vestibular dysfunction, medication in the form of vestibular suppressants does not allow the nervous system to undergo compensation. Thus, long-term medication is not a viable option for individuals with chronic vestibular dysfunction. Because of this, vestibular rehabilitation therapy is a better alternative for long-term vestibular dysfunction. However, some medications, such as anticholinergics, antihistamines, and benzodiazepines, are useful in acute cases (of 5 days or less) for reducing nausea and other secondary symptoms. Because the methods of vestibular rehabilitation therapy differ for different disorders, the form of vestibular dysfunction, ability level, and history of symptoms, each patient must be carefully assessed in order to diagnose vestibular dysfunction and to choose the correct exercises for treatment. In some cases, vestibular rehabilitation may not be the appropriate treatment at all. Vestibular disorders can be diagnosed using several different kinds of assessments, some of which include examination of an individual's ability to maintain posture, balance, and head position. Some diagnostic tests are more easily performed in a clinical setting than others but relay less specific information to the tester, and vice versa. A proper history of symptoms should include what those symptoms are, how often they occur, and under what circumstances, including whether the symptoms are triggered or spontaneous. Other conditions that can be treated with vestibular rehabilitation therapy are symptoms of concussions and dizziness in patients with multiple sclerosis. Magnetic resonance imaging techniques can be used as diagnostic tools to determine the presence of issues that can be treated with vestibular rehabilitation, regardless of whether they are vestibular in nature. The caloric reflex test is designed to test the function of the vestibular system and can determine the cause of vestibular symptoms. The reflex test consists of pouring water into the external auditory canal of a patient and observing nystagmus, or involuntary eye movement. With normal vestibular function, the temperature of the water has an effect on the direction of eye movement. In individuals with peripheral unilateral vestibular hypofunction, nystagmus is absent. This test is used to test bilateral vestibular hypofunction and the degree of central nervous system (CNS) compensation that results. Movement of fluid within the inner ear, known as endolymph, is responsible for the relationship between eye movement and head velocity. The test consists of seating a patient in a rotating chair, rotating the chair to specific velocity, and observing eye movement. In individuals with normal vestibular function, the velocity of eye movement should be equal and opposite that of head movement. Lower rotational velocities are used to assess extent of CNS compensation. Visual perception testing can assess a patient's ability to determine vertically- and horizontally-oriented objects, but with a limited degree of specificity. When asked to align a bar to horizontal or vertical, an individual with normal vestibular function can align the bar within 2.5 degrees of horizontal or vertical. An inability to do so indicates vestibular dysfunction. In some cases, the direction of tilt away from the desired orientation is on the same side as the dysfunction, while in some cases the opposite is true. Using various technologies to assess a person's ability to maintain posture and balance, different patterns of posturography can be determined. Once a pattern is determined, the modalities and inputs that the person relies on to maintain balance can be inferred. Knowing what systems and structures influence a person's stance can suggest different areas of dysfunction and preference. In some cases, the results of vestibular tests are normal, yet the patient experiences vestibular symptoms, especially balance issues and dangerous falls. Some diagnoses that result in non-vestibular dizziness are concussions, Parkinson's disease, cerebellar ataxia, normal-pressure hydrocephalus, leukoaraiosis, progressive supranuclear palsy, and large-fiber peripheral neuropathy. There are also several disorders known as chronic situation-related dizziness disorders. For example, phobic postural vertigo (PPV) occurs when an individual with obsessive-compulsive characteristics experiences a sense of imbalance, despite the absence of balance issues. Chronic subjective dizziness (CSD) is a similar condition characterized by persistent vertigo, hypersensitivity to motion stimuli, and difficulty with precise visual tasks. Both phobic postural vertigo and chronic subjective dizziness may be treated with vestibular rehabilitation therapy or other therapeutic methods such as cognitive behavioral therapy and conditioning.