Evidence-Based Supplement & Herb Guides

Inhibited personality disorder Signs, Risk Factors, and Related Conditions

Understand inhibited personality disorder, its overlap with avoidant personality disorder, key symptoms, possible causes, diagnostic context, similar conditions, and complications that may require professional evaluation.

Inhibited personality disorder is not the most common current diagnostic name in modern clinical practice. When people use this phrase, they are usually referring...

Inflexible personality disorder: Overview, symptoms, signs, causes, and complications

Learn what inflexible personality disorder usually means, how it overlaps with obsessive-compulsive or anankastic personality patterns, what signs may appear in daily life, and when professional evaluation may be important.

“Inflexible personality disorder” is not usually used as a stand-alone formal diagnosis in current psychiatric classification systems. In everyday language, it often describes a...

Infantile autism Early Signs, Behavioral Symptoms, and Complications

Clear, condition-focused overview of infantile autism, including early signs, core symptoms, possible causes, risk factors, diagnostic context, similar conditions, and complications.

Infantile autism is an older clinical term for what is now usually described as autism spectrum disorder when the features are present from early...

Induced delusional disorder: Symptoms, Signs, and Relationship Patterns

Clear explanation of induced delusional disorder, including shared delusions, relationship signs, common symptoms, risk factors, diagnostic context, complications, and urgent warning signs.

Induced delusional disorder is a rare psychotic condition in which a delusional belief becomes shared between two or more closely connected people. It is...

Inadequacy Neurosis: Meaning, Symptoms, Causes, and Mental Health Context

Learn what inadequacy neurosis means today, how it relates to low self-worth and anxiety, and when persistent feelings of inferiority may need professional evaluation.

“Inadequacy neurosis” is an older mental health term that is not used as a formal diagnosis in modern DSM or ICD classification systems. Today,...

Impulse-Control Disorder Overview: What It Means and When Evaluation Matters

Impulse-control disorders involve repeated difficulty resisting harmful urges or aggressive reactions. Learn the main symptoms, signs, causes, risk factors, diagnostic context, and possible complications.

Impulse-control disorders involve repeated difficulty resisting urges, impulses, or aggressive reactions that can lead to harm, distress, legal problems, relationship strain, or serious disruption...

Impulse dysregulation disorder: aggressive, risky, and compulsive behavior patterns

Learn what impulse dysregulation means, how it may appear, what conditions it can resemble, and when repeated impulsive behavior may need professional evaluation.

Impulse dysregulation refers to a pattern of difficulty controlling urges, reactions, or behaviors even when the person understands that the action may be harmful,...

Imposter syndrome: Symptoms, Signs, Causes, and Mental Health Effects

Learn what imposter syndrome means, how it shows up, what causes it, who is most at risk, what it can be confused with, and when professional evaluation may matter.

Imposter syndrome describes a pattern of persistent self-doubt in which a capable person has trouble accepting their own competence, even when there is clear...

Illness Anxiety Disorder Symptoms, Signs, Causes, and Complications

A clear guide to illness anxiety disorder, including symptoms, signs, causes, risk factors, diagnostic context, related conditions, and possible complications.

Illness anxiety disorder is a mental health condition in which fear of having or developing a serious illness becomes persistent, distressing, and hard to...

Identity disorder: Overview, Symptoms, Signs, Causes, Risk Factors, and Complications

Learn what identity disorder can mean, how identity disturbance differs from dissociative identity disorder, which symptoms matter most, and when professional evaluation is important.

Identity problems can be confusing because the word “identity” is used in several different ways in mental health. Some people mean a persistent uncertainty...

Hysteria Symptoms, Signs, Causes, and Modern Clinical Meaning

Understand why hysteria is no longer used as a diagnosis, what symptoms it once described, which modern conditions may overlap, and when professional evaluation matters.

“Hysteria” is an old medical term that is no longer used as a formal diagnosis in modern psychiatry or neurology. In the past, it...

Hypomanic episode Overview: How to Recognize Symptoms and Risks

Learn what a hypomanic episode looks like, how it differs from mania and normal high energy, what can trigger it, and when professional evaluation may be important.

A hypomanic episode is a period of unusually elevated, expansive, or irritable mood with noticeably increased energy or activity. It is more than simply...

Hypomania Symptoms, Signs, Causes, and Risk Factors

Clear, practical guide to hypomania symptoms, signs, causes, risk factors, complications, and how clinicians distinguish it from mania, ADHD, anxiety, substance effects, and normal high energy.

Hypomania is a distinct change in mood, energy, activity, and behavior that is noticeable to others but not as severe as mania. It can...

Hypokinetic mutism signs: how it differs from coma, catatonia, and locked-in syndrome

Learn what hypokinetic mutism means, how it appears, what conditions it can resemble, and why sudden reduced speech or movement may require medical evaluation.

Hypokinetic mutism describes a state in which a person is awake but shows a profound reduction in spontaneous movement and speech. In much of...

Hypochondriasis Symptoms, Signs, Causes, and Complications

Clear overview of hypochondriasis, including modern diagnostic terms, symptoms, behavioral signs, causes, risk factors, related conditions, complications, and when evaluation may matter.

Hypochondriasis describes a persistent, distressing fear of having or developing a serious illness, even when medical evaluation does not support that fear. Many clinicians...

Hypoactive Sexual Desire Disorder Symptoms, Causes, and Diagnostic Context

Understand hypoactive sexual desire disorder, including how it differs from normal low libido, common symptoms, possible causes, risk factors, complications, and when evaluation may be important.

Hypoactive sexual desire disorder describes a persistent, distressing reduction or absence of sexual desire. It is not the same as having a naturally low...

Hypnopompic Hallucinations: How They Differ From Nightmares and Psychosis

Learn what hypnopompic hallucinations feel like, why they happen during waking, what they can be confused with, and when symptoms may need professional evaluation.

Hypnopompic hallucinations are vivid sensory experiences that happen while a person is waking up. They can look, sound, or feel strikingly real, even though...

Hypnagogic Hallucinations Symptoms, Causes, Signs, and Risk Factors

Hypnagogic hallucinations are vivid sleep-onset experiences that can involve sights, sounds, body sensations, or a sensed presence. Learn how they differ from dreams, nightmares, sleep paralysis, narcolepsy symptoms, and waking hallucinations, plus when evaluation may be important.

Hypnagogic hallucinations are vivid sensory experiences that happen as a person is falling asleep. They can involve seeing shapes, faces, animals, people, lights, or...

Hypervigilance Signs and Symptoms in Trauma, Anxiety, and Stress

Hypervigilance is a persistent state of threat monitoring that can affect sleep, concentration, relationships, and daily functioning. Learn the symptoms, causes, risk factors, complications, and diagnostic context.

Hypervigilance is a state of heightened watchfulness in which the mind and body stay on alert for possible danger, even when the immediate situation...

Hyperthymia Explained: Signs, Causes, and Diagnostic Context

Hyperthymia is a persistent high-energy temperament that can be adaptive or impairing. Learn how it differs from hypomania, what signs matter, and when symptoms may signal a broader mood disorder.

Hyperthymia usually refers to hyperthymic temperament: a long-standing pattern of unusually high energy, optimism, confidence, sociability, and drive. It is not the same as...