Since astasis itself is more a symptom than a disease, it is more often seen associated with other signs and symptoms. People who have astasis often experience

- Odd gyrations

- Tightrope balancing deficits (in which a person attempts to balance on a tightrope in order to test balance and motor coordination)

- Near falling deficits (which is a test in which the patient is slightly pushed in order to check their ability to regain posture)

- Exaggerated effort deficits (which is an overcompensation test used to determine motor coordination ability)

- Atypical postures and weakness

- Paralysis

- Jumping fits (in which motor control is partially or totally lost)

- Tremors

One study described a patient with astasis as lying in bed with a normal body posture. When the patient was sitting, he tilted his body to the left. When he was asked to stand up, the patient rotated his trunk axis to the left (left shoulder going backwards), and tilted his body to that same side, showing resistance to passive correction of posture in both of these planes. He was unable to stand and fell backwards and towards the left.

Damage to the peripheral nerves coming from the legs to the somatosensory area is the leading candidate for the cause of astasis. These damaged nerves prevent feedback for stabilization of posture for patients with astasis. This causes a disturbance in postural movements, such as a swaying around the legs and hip joints. This swaying may be seen only when a patient in standing still, and may disappear before walking, indicating that these patients exhibit astasia without abasia. This impairment of sensation is not always required for the sensation to develop. However, impairment often worsens astasia.

Astasia-abasia refers to the inability to either stand or walk in a normal manner. Astasia refers to the inability to stand upright unassisted. Abasia refers to lack of motor coordination in walking. The term "abasia" literally means that the base of gait (the lateral distance between the two feet) is inconstant or unmeasurable. When seen in conversion disorder, the gait is bizarre and is not suggestive of a specific organic lesion: often the patient sways wildly and nearly falls, recovering at the last moment.

An acquired total inability to stand and walk can be seen in true neurological diseases, including stroke, Parkinson's disease, damage to the cerebellum, Guillain–Barré syndrome, normal pressure hydrocephalus and many others. In normal pressure hydrocephalus, for example, when the condition remains untreated, the patient's gait becomes shortened, with frequent shuffling and falls; eventually standing, sitting, and even rolling over in bed become impossible. This advanced state is referred to as "hydrocephalic astasia-abasia".

Astasia and/or abasia are associated with the corresponding fears of walking and/or standing, variously called stasophobia, basophobia, stasiphobia, basiphobia, stasobasophobia, stasibasiphobia, etc., sometimes turning into pathological forms, i.e. phobias.

Abasia (from Greek: "a-", without and "basis", step) is the inability to walk owing to impairment in motor coordination.

The term covers a spectrum of medical disorders such as:

- choreic abasia: caused by chorea of the legs

- paralytic abasia: caused by paralysis of the leg muscles

- spastic abasia: caused by spastic stiffening of the leg muscles

- trembling abasia: caused by trembling of the legs

Abasia is frequently accompanied by astasis, an inability to stand, see Astasia-abasia.

When balance is impaired, an individual has difficulty maintaining upright orientation. For example, an individual may not be able to walk without staggering, or may not even be able to stand. They may have falls or near-falls. The symptoms may be recurring or relatively constant. When symptoms exist, they may include:

- A sensation of dizziness or vertigo.

- Lightheadedness or feeling woozy.

- Problems reading and difficulty seeing.

- Disorientation.

Some individuals may also experience nausea and vomiting, diarrhea, faintness, changes in heart rate and blood pressure, fear, anxiety, or panic. Some reactions to the symptoms are fatigue, depression, and decreased concentration. The symptoms may appear and disappear over short time periods or may last for a longer period.

Cognitive dysfunction (disorientation) may occur with vestibular disorders. Cognitive deficits are not just spatial in nature, but also include non-spatial functions such as object recognition memory. Vestibular dysfunction has been shown to adversely affect processes of attention and increased demands of attention can worsen the postural sway associated with vestibular disorders. Recent MRI studies also show that humans with bilateral vestibular damage undergo atrophy of the hippocampus which correlates with their degree of impairment on spatial memory tasks.

NPH may exhibit a classic triad of clinical findings (known as the Adams triad or Hakim's triad) of urinary incontinence, gait disturbance, and dementia (commonly referred to as "wet, wacky and wobbly" or "weird walking water").

- Gait disturbance is typically the initial and most prominent symptom of the triad and may be progressive, due to expansion of the ventricular system, particularly at the level of the lateral ventricles, leading to traction on the corticospinal tract motor fibers descending to the lumbosacral spinal cord. The gait disturbance can be classified as mild (cautious gait or difficulty with tandem gait), marked (evident difficulty walking or considerable unstable gait) or severe (unaided gait not possible) In the early stages, most often this gait disturbance occurs in the form of unsteadiness and impaired balance, especially when encountering stairs and curbs. Weakness and tiredness of the legs may also be part of the complaint, although examination discloses no paresis or ataxia. Often a mobility aid is used for added stability, once the patient has reached the mild to marked stage. Such aids may include a quad cane or wheeled walker. The patient's gait at the marked stage will often show a decrease in step height and foot-floor clearance, as well as a decrease in walking speed. This style is often referred to as a magnetic gait, in which the feet appear to be stuck to the walking surface, and is considered the characteristic gait disturbance of NPH. The gait may begin to mimic a Parkinsonian gait, with short shuffling steps and stooped, forward-leaning posture, but there is no rigidity or tremor. An increased tendency to fall backwards is also seen, and a broad-based gait may be employed by the patient in order to increase their base of support and thereby their stability. In the very late stages, the patient can progress from an inability to walk, to an inability to stand, sit, rise from a chair or turn over in bed; this advanced stage is referred to as "hydrocephalic astasia-abasia".

- Dementia is predominantly frontal lobe in nature and of the subcortical type of dementia. It presents in the form of abulia, forgetfulness, inertia, inattention, decreased speed of complex information procession (also described as a dullness in thinking and actions), and disturbed manipulation of acquired knowledge, which is reflective of the loss of integrity of the frontal lobes. Memory problems are usually a component of the overall problem and have been predominant in some cases, which can lead to the misdiagnosis of Alzheimer's disease. However, in NPH there may be an obvious discrepancy between (often severely) impaired recall and intact or much less impaired recognition. The dementia is thought to result from traction on frontal and limbic fibers that also run in the periventricular region.

- Urinary incontinence appears late in the illness, and is found to be of the spastic hyperreflexic, increased-urgency type associated with decreased inhibition of bladder contractions and detrusor instability. In the most severe cases, bladder hyperreflexia is associated with a lack of concern for micturition due to the severe frontal lobe cognitive impairment. This is also known as "frontal lobe incontinence", where the patient becomes indifferent to their recurrent urinary symptoms.

Problems with balance can occur when there is a disruption in any of the vestibular, visual, or proprioceptive systems. Abnormalities in balance function may indicate a wide range of pathologies from causes like inner ear disorders, low blood pressure, brain tumors, and brain injury including stroke.

Many different terms are often used for dizziness, including lightheaded, floating, woozy, giddy, confused, helpless, or fuzzy. Vertigo, Disequilibrium and pre-syncope are the terms in use by most physicians and have more precise definitions.

Vertigo

Vertigo is the sensation of spinning or having the room spin about you. Most people find vertigo very disturbing and report associated nausea and vomiting.

Disequilibrium

Disequilibrium is the sensation of being off balance, and is most often characterized by frequent falls in a specific direction. This condition is not often associated with nausea or vomiting.

Presyncope

Pre-syncope is a feeling of lightheadedness or simply feeling faint. Syncope, by contrast, is actually fainting. A circulatory system deficiency, such as low blood pressure, can contribute to a feeling of dizziness when one suddenly stands up.

Problems in the skeletal or visual systems, such as arthritis or eye muscle imbalance, may also cause balance problems.

Aboulia has been known to clinicians since 1838. However, in the time since its inception, the definition of aboulia has been subjected to many different forms, some contradictory. Aboulia has been described as a loss of drive, expression, loss of behavior and speech output, slowing and prolonged speech latency, and reduction of spontaneous thought content and initiative. The clinical features most commonly associated with aboulia are:

- Difficulty in initiating and sustaining purposeful movements

- Lack of spontaneous movement

- Reduced spontaneous speech

- Increased response-time to queries

- Passivity

- Reduced emotional responsiveness and spontaneity

- Reduced social interactions

- Reduced interest in usual pastimes

Especially in patients with progressive dementia, it may affect feeding. Patients may continue to chew or hold food in their mouths for hours without swallowing it. The behavior may be most evident after these patients have eaten part of their meals and no longer have strong appetites.

Normal pressure hydrocephalus (NPH), also termed Hakim's syndrome and symptomatic hydrocephalus, is a type of brain malfunction caused by expansion of the lateral cerebral ventricles and distortion of the fibers in the corona radiata. Its typical symptoms are urinary incontinence, dementia, and gait disturbance. CSF pressure is usually normal. Ventricles are chronically dilated.

The name “normal pressure” came out of a 1965 medical paper describing cases of hydrocephalus where the symptoms occurred in the presence of supposedly normal cerebrospinal-fluid pressure. The paper was published before continuous pressure-recording techniques were available. We now know that “normal pressure” is a misnomer.

The usual treatment is surgical installation of a ventriculoperitoneal shunt to drain excess CSF into the lining of the abdomen where the CSF will eventually be absorbed.

Aboulia or abulia (from , meaning "will", with the prefix -a), in neurology, refers to a lack of will or initiative and can be seen as a disorder of diminished motivation (DDM). Aboulia falls in the middle of the spectrum of diminished motivation, with apathy being less extreme and akinetic mutism being more extreme than aboulia. A patient with aboulia is unable to act or make decisions independently. It may range in severity from subtle to overwhelming. It is also known as Blocq's disease (which also refers to abasia and astasia-abasia). Aboulia was originally considered to be a disorder of the will.

Conversion disorder begins with some stressor, trauma, or psychological distress. Usually the physical symptoms of the syndrome affect the senses or movement. Common symptoms include blindness, partial or total paralysis, inability to speak, deafness, numbness, difficulty swallowing, incontinence, balance problems, seizures, tremors, and difficulty walking. These symptoms are attributed to conversion disorder when a medical explanation for the afflictions cannot be found. Symptoms of conversion disorder usually occur suddenly. Conversion disorder is typically seen in individuals aged 10 to 35, and affects between 0.011% and 0.5% of the general population.

Conversion disorder can present with motor or sensory symptoms including any of the following:

Motor symptoms or deficits:

- Impaired coordination or balance

- Weakness/paralysis of a limb or the entire body (hysterical paralysis or motor conversion disorders)

- Impairment or loss of speech (hysterical aphonia)

- Difficulty swallowing (dysphagia) or a sensation of a lump in the throat

- Urinary retention

- Psychogenic non-epileptic seizures or convulsions

- Persistent dystonia

- Tremor, myoclonus or other movement disorders

- Gait problems (astasia-abasia)

- Loss of consciousness (fainting)

Sensory symptoms or deficits:

- Impaired vision (hysterical blindness), double vision

- Impaired hearing (deafness)

- Loss or disturbance of touch or pain sensation

Conversion symptoms typically do not conform to known anatomical pathways and physiological mechanisms. It has sometimes been stated that the presenting symptoms tend to reflect the patient's own understanding of anatomy and that the less medical knowledge a person has, the more implausible are the presenting symptoms. However, no systematic studies have yet been performed to substantiate this statement.

Conversion disorder presents with symptoms that typically resemble a neurological disorder such as stroke, multiple sclerosis, epilepsy or hypokalemic periodic paralysis. The neurologist must carefully exclude neurological disease, through examination and appropriate investigations. However, it is not uncommon for patients with neurological disease to also have conversion disorder.

In excluding neurological disease, the neurologist has traditionally relied partly on the presence of positive signs of conversion disorder, i.e. certain aspects of the presentation that were thought to be rare in neurological disease but common in conversion. The validity of many of these signs has been questioned, however, by a study showing that they also occur in neurological disease. One such symptom, for example, is "la belle indifférence", described in DSM-IV as "a relative lack of concern about the nature or implications of the symptoms". In a later study, no evidence was found that patients with functional symptoms are any more likely to exhibit this than patients with a confirmed organic disease. In DSM-V, "la belle indifférence" was removed as a diagnostic criteria.

Another feature thought to be important was that symptoms tended to be more severe on the non-dominant (usually left) side of the body. There have been a number of theories about this, such as the relative involvement of cerebral hemispheres in emotional processing, or more simply, that it was "easier" to live with a functional deficit on the non-dominant side. However, a literature review of 121 studies established that this was not true, with publication bias the most likely explanation for this commonly held view. Although agitation is often assumed to be a positive sign of conversion disorder, release of epinephrine is a well-demonstrated cause of paralysis from hypokalemic periodic paralysis.

Misdiagnosis does sometimes occur. In a highly influential study from the 1960s, Eliot Slater demonstrated that misdiagnoses had occurred in one third of his 112 patients with conversion disorder. Later authors have argued that the paper was flawed, however, and a meta-analysis has shown that misdiagnosis rates since that paper was published are around 4%, the same as for other neurological diseases.

Closely related to postural control is the sensation of vertigo: a warning signal created by a loss of postural control when the distance between the observer and visible stationary objects becomes too large, and caused by a dysfunction of the vestibular system in the inner ear. In short, it is the feeling of motion when one is actually stationary. Symptoms of vertigo include dizziness, nausea, vomiting, shortness of breath, and the inability to walk or stand. Some individuals are more reliant on visual cues to control posture than others. Vestibular sensations can arise when unsound information is detected along the sensory channels (this happens even to those with normal vestibular function), and feelings of vertigo can result in people with postural control issues.

The fear of falling (FOF), also referred to as basophobia (or basiphobia), is a natural fear and is typical of most humans and mammals, in varying degrees of extremity. It differs from acrophobia (the fear of heights), although the two fears are closely related. The fear of falling encompasses the anxieties accompanying the sensation and the possibly dangerous effects of falling, as opposed to the heights themselves. Those who have little fear of falling may be said to have a head for heights. Basophobia is sometimes associated with astasia-abasia, the fear of walking/standing erect.