Tremor in the context of "Serotonin syndrome"

Crying is the dropping of tears (or welling of tears in the eyes) in response to an emotional state or physical pain. Emotions that can lead to crying include sadness, anger, joy, and fear. Crying can also be caused by relief from a period of stress or anxiety, or as an empathetic response. The act of crying has been defined as "a complex secretomotor phenomenon characterized by the shedding of tears from the lacrimal apparatus, without any irritation of the ocular structures", instead, giving a relief which protects from conjunctivitis. A related medical term is lacrimation, which also refers to the non-emotional shedding of tears. Various forms of crying are known as sobbing, weeping, wailing, whimpering, bawling, and blubbering.

For crying to be described as sobbing, it usually has to be accompanied by a set of other symptoms, such as slow but erratic inhalation, occasional instances of breath holding, and muscular tremor.

Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor and non-motor systems. The motor symptoms are collectively called parkinsonism and include tremors, bradykinesia (slowness in initiating movement), rigidity, and postural instability (difficulty maintaining balance). Non-motor symptoms such as dysautonomia (autonomic nervous system failures), sleep abnormalities, anosmia (decreased ability to smell), and behavioral changes or neuropsychiatric problems, such as cognitive impairment, psychosis, and anxiety, may appear at any stage of the disease. Symptoms typically develop gradually and non-motor issues become more prevalent as the disease progresses.

Most Parkinson's disease cases are idiopathic, though contributing factors have been identified. Pathophysiology involves progressive degeneration of nerve cells in the substantia nigra, a midbrain region that provides dopamine to the basal ganglia, a system involved in voluntary motor control. The cause of this cell death is poorly understood, but involves the aggregation of alpha-synuclein into Lewy bodies within neurons. Other potential factors involve genetic and environmental influences, medications, lifestyle, and prior health conditions.

Hyperthyroidism is a endocrine disease in which the thyroid gland produces excessive amounts of thyroid hormones. Thyrotoxicosis is a condition that occurs due to elevated levels of thyroid hormones of any cause and therefore includes hyperthyroidism. Some, however, use the terms interchangeably. Signs and symptoms vary between people and may include irritability, muscle weakness, sleeping problems, a fast heartbeat, heat intolerance, diarrhea, enlargement of the thyroid, hand tremor, and weight loss. Symptoms are typically less severe in the elderly and during pregnancy. An uncommon but life-threatening complication is thyroid storm in which an event such as an infection results in worsening symptoms such as confusion and a high temperature; this often results in death. The opposite is hypothyroidism, when the thyroid gland does not make enough thyroid hormone.

Graves' disease is the cause of about 50% to 80% of the cases of hyperthyroidism in the United States. Other causes include multinodular goiter, toxic adenoma, inflammation of the thyroid, eating too much iodine, and too much synthetic thyroid hormone. A less common cause is a pituitary adenoma. The diagnosis may be suspected based on signs and symptoms and then confirmed with blood tests. Typically blood tests show a low thyroid stimulating hormone (TSH) and raised T₃ or T₄. Radioiodine uptake by the thyroid, thyroid scan, and measurement of antithyroid autoantibodies (thyroidal thyrotropin receptor antibodies are positive in Graves' disease) may help determine the cause.

Panic attacks are sudden periods of intense fear and discomfort that may include palpitations, otherwise defined as a rapid, irregular heartbeat, sweating, chest pain or discomfort, shortness of breath, trembling, dizziness, numbness, confusion, or a sense of impending doom or loss of control. Typically, these symptoms are the worst within ten minutes of onset and can last for roughly 30 minutes, though they can vary anywhere from seconds to hours. While they can be extremely distressing, panic attacks themselves are not physically dangerous.

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) defines them as "an abrupt surge of intense fear or intense discomfort that reaches a peak within minutes and during which time four or more of the following symptoms occur." These symptoms include, but are not limited to, the ones mentioned above.

Social anxiety disorder (SAD), also known as social phobia, is an anxiety disorder characterized by sentiments of fear and anxiety in social situations, causing considerable distress and impairing ability to function in at least some aspects of daily life. These fears can be triggered by perceived or actual scrutiny from others. Individuals with social anxiety disorder fear negative evaluations from other people.

Physical symptoms often include excessive blushing, excessive sweating, trembling, palpitations, rapid heartbeat, muscle tension, shortness of breath, and nausea. Panic attacks can also occur under intense fear and discomfort. Some affected individuals may use alcohol or other drugs to reduce fears and inhibitions at social events. It is common for those with social phobia to self-medicate in this fashion, especially if they are undiagnosed, untreated, or both; this can lead to alcohol use disorder, eating disorders, or other kinds of substance use disorders. According to ICD-10 guidelines, the main diagnostic criteria of social phobia are fear of being the focus of attention, or fear of behaving in a way that will be embarrassing or humiliating, avoidance and anxiety symptoms. Standardized rating scales can be used to screen for social anxiety disorder and measure the severity of anxiety.

Myoclonus is a brief, involuntary, irregular (lacking rhythm) twitching of a muscle, a joint, or a group of muscles, different from clonus, which is rhythmic or regular. Myoclonus (myo- "muscle", clonus "spasm") describes a medical sign and, generally, is not a diagnosis of a disease. It belongs to the hyperkinetic movement disorders, among tremor and chorea for example. These myoclonic twitches, jerks, or seizures are usually caused by sudden muscle contractions (positive myoclonus) or brief lapses of contraction (negative myoclonus). The most common circumstance under which they occur is while falling asleep (hypnic jerk). Myoclonic jerks occur in healthy people and are experienced occasionally by everyone. However, when they appear with more persistence and become more widespread they can be a sign of various neurological disorders. Hiccups are a kind of myoclonic jerk specifically affecting the diaphragm. When a spasm is caused by another person it is known as a provoked spasm. Shuddering attacks in babies fall in this category.

Myoclonic jerks may occur alone or in sequence, in a pattern or without pattern. They may occur infrequently or many times each minute. Most often, myoclonus is one of several signs in a wide variety of nervous system disorders such as multiple sclerosis, Parkinson's disease, dystonia, cerebral palsy, Alzheimer's disease, Gaucher's disease, subacute sclerosing panencephalitis, Creutzfeldt–Jakob disease (CJD), serotonin toxicity, some cases of Huntington's disease, some forms of epilepsy, and occasionally in intracranial hypotension.

Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by tremors, slow movement, muscle rigidity, postural instability (collectively known as parkinsonism), autonomic dysfunction and ataxia. This is caused by progressive degeneration of neurons in several parts of the brain including the basal ganglia, inferior olivary nucleus, and cerebellum. MSA was first described in 1960 by Milton Shy and Glen Drager and was then known as Shy–Drager syndrome.

Many people affected by MSA experience dysfunction of the autonomic nervous system, which commonly manifests as orthostatic hypotension, impotence, loss of sweating, dry mouth and urinary retention and incontinence. Palsy of the vocal cords is an important and sometimes initial clinical manifestation of the disorder.

Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), rigidity, and postural instability.

Both hypokinetic features (bradykinesia and akinesia) and hyperkinetic features (cogwheel rigidity and tremors at rest) are displayed in parkinsonism. These are the four motor signs that are found in Parkinson's disease (PD) – after which Parkinsonism is named – and in dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and many other conditions.

Dystonia is a neurological hyperkinetic movement disorder in which sustained or repetitive muscle contractions occur involuntarily, resulting in twisting and repetitive movements or abnormal fixed postures. The movements may resemble a tremor. Dystonia is often intensified or exacerbated by physical activity, and symptoms may progress into adjacent muscles.

The disorder may be hereditary or caused by other factors such as birth-related or other physical trauma, infection, poisoning (e.g., lead poisoning) or reaction to pharmaceutical drugs, particularly neuroleptics, or stress. Treatment must be highly customized to the needs of the individual and may include oral medications, chemodenervation botulinum neurotoxin injections, physical therapy, or other supportive therapies, and surgical procedures such as deep brain stimulation.

Chills is a feeling of coldness occurring during a high fever, but sometimes is also a common symptom which occurs alone in specific people. It occurs during fever due to the release of cytokines and prostaglandins as part of the inflammatory response, which increases the set point for body temperature in the hypothalamus. The increased set point causes the body temperature to rise (pyrexia), but also makes the patient feel cold or chills until the new set point is reached. Shivering also occurs along with chills because the patient's body produces heat during muscle contraction in a physiological attempt to increase body temperature to the new set point. When it does not accompany a high fever, it is normally a light chill.

Sometimes a chill of medium power and short duration may occur during a scare, especially in scares of fear, commonly interpreted like or confused by trembling.

Generalized anxiety disorder (GAD) is an anxiety disorder characterized by excessive, uncontrollable, and often irrational worry about events or activities. Worry often interferes with daily functioning. Individuals with GAD are often, but not necessarily, overly concerned about everyday matters such as health, finances, death, family, relationship concerns, or work difficulties. Symptoms may include excessive worry, restlessness, trouble sleeping, exhaustion, irritability, sweating, and trembling.

Symptoms must be consistent and ongoing, persisting at least six months for a formal diagnosis. Individuals with GAD often have other disorders including other psychiatric disorders, substance use disorder, or obesity, and may have a history of trauma or family with GAD. Clinicians use screening tools such as the GAD-7 and GAD-2 questionnaires to determine if individuals may have GAD and warrant formal evaluation for the disorder. In addition, screening tools may enable clinicians to evaluate the severity of GAD symptoms.

Alcohol withdrawal syndrome (AWS) is a set of symptoms that can occur following a reduction in or cessation of alcohol use after a period of excessive use. Symptoms typically include anxiety, shakiness, sweating, vomiting, fast heart rate, and a mild fever. More severe symptoms may include seizures, and delirium tremens (DTs); which can be fatal in untreated patients. Symptoms start at around 6 hours after the last drink. Peak incidence of seizures occurs at 24 to 36 hours and peak incidence of delirium tremens is at 48 to 72 hours.

Alcohol withdrawal may occur in those who are alcohol dependent. This may occur following a planned or unplanned decrease in alcohol intake. The underlying mechanism involves a decreased responsiveness of GABA receptors in the brain. The withdrawal process is typically followed using the Clinical Institute Withdrawal Assessment for Alcohol scale (CIWA-Ar).

Extrapyramidal symptoms (EPS) are symptoms that are archetypically associated with the extrapyramidal system of the brain. When such symptoms are caused by medications or other drugs, they are also known as extrapyramidal side effects (EPSE). The symptoms can be acute (short-term) or chronic (long-term). They include movement dysfunction such as dystonia (continuous spasms and muscle contractions), akathisia (may manifest as motor restlessness), parkinsonism characteristic symptoms such as rigidity, bradykinesia (slowness of movement), tremor, and tardive dyskinesia (irregular, jerky movements). Extrapyramidal symptoms are a reason why subjects drop out of clinical trials of antipsychotics; of the 213 (14.6%) subjects that dropped out of one of the largest clinical trials of antipsychotics (the CATIE trial [Clinical Antipsychotic Trials for Intervention Effectiveness], which included 1460 randomized subjects), 58 (27.2%) of those discontinuations were due to EPS.

Cerebral palsy (CP) is a group of movement disorders that appear in early childhood. Signs and symptoms vary among people and over time, but include poor coordination, stiff muscles, weak muscles, and tremors. There may be problems with sensation, vision, hearing, and speech. Often, babies with cerebral palsy do not roll over, sit, crawl or walk as early as other children. Other symptoms may include seizures and problems with thinking or reasoning. While symptoms may get more noticeable over the first years of life, underlying problems do not worsen over time.

Cerebral palsy is caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture. Most often, the problems occur during pregnancy, but may occur during childbirth or shortly afterwards. Often, the cause is unknown. Risk factors include preterm birth, being a twin, certain infections or exposure to methylmercury during pregnancy, a difficult delivery, and head trauma during the first few years of life. A study published in 2024 suggests that inherited genetic causes play a role in 25% of cases, where formerly it was believed that 2% of cases were genetically determined.

Benzodiazepine withdrawal syndrome (BZD withdrawal) is the cluster of signs and symptoms that may emerge when a person who has been taking benzodiazepines as prescribed develops a physical dependence on them and then reduces the dose or stops taking them without a safe taper schedule.

Typically, benzodiazepine withdrawal is characterized by sleep disturbance, irritability, increased tension and anxiety, depression, panic attacks, hand tremor, shaking, sweating, difficulty with concentration, confusion and cognitive difficulty, memory problems, dry mouth, nausea and vomiting, diarrhea, loss of appetite and weight loss, burning sensations and pain in the upper spine, palpitations, headache, nightmares, tinnitus, muscular pain and stiffness, and a host of perceptual changes. More serious symptoms may also occur such as depersonalization, restless legs syndrome, seizures, and suicidal ideation.