Disease and conditions 

Loss of the gag reflex signals disruption of cranial nerves IX/X or brainstem function, placing patients at high risk of aspiration. Rapid airway protection, swallowing assessment, and neurologic evaluation are essential.

A sunken anterior fontanel is a hallmark sign of dehydration in infants, reflecting reduced intracranial and extracellular fluid volume. Prompt assessment, fluid replacement, and electrolyte monitoring are critical to prevent shock and complications.

A bulging fontanel in infants is a key indicator of increased intracranial pressure, often secondary to infection, hydrocephalus, or trauma. Prompt recognition, emergency stabilization, and investigation of underlying causes are essential to prevent neurological deterioration.

Flank pain, ranging from dull ache to severe colicky pain, commonly signals renal or upper urinary tract disease, obstruction, or trauma. Early recognition, thorough assessment, and prompt intervention are crucial to prevent complications and address underlying causes.

Fever (pyrexia) is a temporary rise in body temperature caused by infection, immune disorders, or other systemic conditions. While mild fevers are common, very high or persistent fevers may signal serious illness and require urgent medical attention.

Fetor hepaticus is a distinctive musty, sweet breath odor indicating advanced hepatic encephalopathy, a life-threatening complication of severe liver disease. Its detection requires urgent assessment of consciousness, airway, and hemodynamic status, with management focused on reducing blood ammonia and supporting vital functions.

Fecal incontinence is the involuntary passage of feces due to impaired anal sphincter control, resulting from gastrointestinal, neurologic, or psychological disorders, surgery, or drug effects. Its severity, pattern, and associated symptoms guide diagnosis and individualized management.

Fatigue is a subjective sensation of persistent tiredness, lack of energy, or exhaustion, often worsened by activity and relieved by rest. It may result from normal physical exertion, psychological stress, or underlying medical conditions such as infection, endocrine disorders, cardiovascular disease, or metabolic imbalances.

Fasciculations are involuntary, visible muscle twitches caused by spontaneous motor nerve discharge, which can be benign or indicate serious neuromuscular disorders. Prompt evaluation is essential to identify underlying causes such as motor neuron disease, spinal cord lesions, or toxin exposure.

Eye discharge, eye pain, and exophthalmos are critical ophthalmic signs that may indicate infections, trauma, inflammation, systemic disease, or vision-threatening emergencies. Accurate evaluation, timely intervention, and patient education are essential to preserve vision and ocular health.

Eye pain can range from mild discomfort to severe, vision-threatening pain caused by ocular or systemic disorders. Prompt assessment, accurate diagnosis, and emergency interventions when needed are essential for preserving vision and ocular health.

Eye discharge is a common sign of ocular or systemic disease, ranging from serous to purulent secretions, and may indicate infections, inflammation, or systemic conditions. Early identification of the cause and prompt management are critical to prevent vision-threatening complications.

Exophthalmos is the abnormal protrusion of one or both eyeballs caused by orbital inflammation, tumors, infection, or autoimmune disorders. Prompt diagnosis, identification of the underlying cause, and timely management are essential to prevent vision loss and complications.

Erythema is a clinical manifestation of skin inflammation or irritation caused by diverse factors including infections, autoimmune disorders, drug reactions, and burns. Recognizing the underlying cause, assessing severity, and providing timely emergency interventions and supportive care are essential for effective management in healthcare settings.

Epistaxis is bleeding from the nose, usually anterior but occasionally posterior, and can range from mild to life-threatening. Causes include trauma, coagulation disorders, hypertension, infections, tumors, systemic diseases, drugs, and chemical irritants.

Enuresis is nighttime bed-wetting in children ≥5 years (girls) or ≥6 years (boys), classified as primary or secondary. Causes include detrusor hyperactivity, UTIs, obstruction, diabetes, neurologic disorders, sleep disturbances, psychological stress, and hormonal or structural factors.

Leg edema is the accumulation of excess interstitial fluid in one or both legs, caused by venous, cardiac, renal, infectious, or traumatic conditions. Clinical assessment, including history, examination, and diagnostic studies, guides management and prevention of complications.

Facial edema is swelling of the face that may be localized or generalized, developing gradually or abruptly, and can result from trauma, allergy, systemic disorders, or drug reactions. Severe cases may compromise the airway, requiring urgent intervention, while mild cases often precede peripheral or generalized edema.

Arm edema is the accumulation of excess interstitial fluid in one or both arms, often due to trauma, vascular disorders, toxins, or treatment-related complications. Early assessment, elevation, and careful monitoring are essential to prevent complications such as neurovascular compromise and lymphedema.

Generalized edema is the widespread accumulation of interstitial fluid throughout the body, often resulting from cardiac, renal, hepatic, endocrine, or nutritional disorders. Its severity ranges from mild, barely noticeable swelling to massive anasarca, frequently accompanied by weight gain, dyspnea, and skin changes.

Earache (otalgia) is pain in the external, middle, or inner ear caused by infection, obstruction, trauma, or referred pain, often accompanied by hearing loss, discharge, or vertigo. Its onset, character, and associated symptoms help differentiate underlying causes such as otitis externa, otitis media, cerumen impaction, or barotrauma.

Dysuria is painful or difficult urination often accompanied by urinary frequency, urgency, or hesitancy, usually resulting from lower urinary tract irritation or infection. Its timing, associated symptoms, and patient history help identify underlying causes such as cystitis, prostatitis, urinary obstruction, or chemical irritation.

Dystonia is characterized by slow, involuntary, twisting movements of large muscle groups, often aggravated by stress and relieved by sleep. It may be hereditary, idiopathic, or secondary to neurological disorders or certain drugs.

Dyspnea is the subjective sensation of difficult or uncomfortable breathing, ranging from mild to severe. It can result from respiratory, cardiac, neuromuscular, or systemic conditions, with onset and pattern helping to distinguish underlying causes.

Dysphagia is a symptom of impaired swallowing caused by structural, neuromuscular, infectious, malignant, or systemic conditions, often classified by the swallowing phase affected.
Recognizing distinguishing features of each cause is essential for timely diagnosis, prevention of aspiration, and appropriate management.

Dyspepsia is a condition characterized by upper abdominal discomfort, including bloating, early satiety, and epigastric pain, often related to meals. It may result from functional disorders, peptic ulcers, GERD, or medication effects, and requires evaluation to rule out serious pathology.

Dysmenorrhea is a prevalent cause of painful menstruation caused by primary prostaglandin-mediated uterine contractions or secondary pelvic pathology. Accurate history and physical exam guide diagnosis, with NSAIDs and lifestyle measures as mainstays of treatment.

Dysarthria is a motor speech disorder resulting from neurological injury affecting speech muscles, with diverse etiologies including degenerative diseases, stroke, toxins, and infections. Diagnosis requires detailed neurologic and speech assessment, and management involves treating underlying causes and supportive rehabilitation.

Drooling refers to the unintentional loss of saliva from the mouth, commonly associated with neurological disorders, oral structural abnormalities, or medication side effects. It requires assessment of underlying causes to guide appropriate management.

Absent doll’s eye sign is a vital neurological bedside test indicating brainstem integrity. It assists in localizing lesions, assessing coma severity, and guiding further diagnostic and therapeutic interventions.

Dizziness results from disrupted integration of vestibular, visual, and proprioceptive inputs or reduced cerebral perfusion, causing imbalance or faintness. Vertigo specifically arises from vestibular system dysfunction, producing a false sensation of spinning or motion.

Diplopia is the perception of double vision caused by dysfunction of extraocular muscles or cranial nerves controlling them. It may be monocular or binocular and can result from neurologic, muscular, orbital, or systemic disorders.

Diarrhea is the frequent passage of loose, watery stools, caused by infections, inflammatory diseases, malabsorption, or medication effects. Severe cases may lead to dehydration or shock, requiring prompt fluid resuscitation and investigation of the underlying cause.

Diaphoresis is excessive sweating triggered by physical, emotional, or pathological stress, often indicating underlying conditions like hypoglycemia, infection, or myocardial infarction. It may be localized or generalized and requires urgent evaluation when accompanied by systemic symptoms.

Depression is a mood disorder marked by persistent sadness, loss of interest, and impaired daily functioning. It requires timely diagnosis, risk assessment for suicide, and combined medical and psychological treatment for recovery.

Hypoactive deep tendon reflexes indicate reduced or absent reflex activity due to dysfunction in the reflex arc. They are associated with neuromuscular, metabolic, toxic, and structural disorders and require careful clinical evaluation to determine the underlying cause.

Are exaggerated reflex responses often caused by upper motor neuron lesions or electrolyte imbalances like hypocalcemia or hypomagnesemia. They may signal serious neurologic, metabolic, or obstetric conditions and require thorough clinical evaluation and appropriate management.

Decorticate posture is a clinical sign of corticospinal tract damage, marked by arm flexion and leg extension, often due to severe brain injury. It indicates a serious neurological condition but has a better prognosis than decerebrate posture.

Decerebrate posture is a severe abnormal motor response indicating brain stem damage. It signals a grave neurological insult and requires urgent airway support, diagnostic evaluation, and neurocritical care.

Cyanosis is a bluish discoloration of the skin or mucosa due to inadequate oxygenation or perfusion. It signals serious cardiopulmonary or vascular pathology requiring prompt evaluation and oxygenation support.