Disease and conditions 

Decreased Level of Consciousness (LOC) is a critical sign ranging from lethargy to coma, caused by neurologic, metabolic, infectious, toxic, or systemic conditions, and requires prompt assessment and intervention. Early recognition using the Glasgow Coma Scale and timely emergency management can prevent life-threatening complications and improve outcomes.

Hemianopsia is a visual field defect characterized by loss of vision in one-half of the normal visual field of one or both eyes. Complete homonymous hemianopsia, in which the same half of the visual field is lost in both eyes, usually indicates a lesion of the optic tract or optic radiation, whereas incomplete defects affecting less than half the field in both eyes suggest an occipital lobe lesion. Lesions of the optic chiasm, tract, or radiation often impair color vision and visual perception.

Polydipsia is excessive thirst often caused by endocrine, renal, or psychiatric disorders, certain drugs, or electrolyte imbalances, and may be accompanied by polyuria, nocturia, and signs of dehydration. Evaluation involves detailed history, physical examination, monitoring fluid balance, and addressing underlying causes such as diabetes, hypercalcemia, or psychogenic factors.

Pulsus alternans is a beat-to-beat variation in pulse amplitude, usually indicating severe left-sided heart failure, and may be accompanied by a ventricular gallop. Detection requires careful palpation or sphygmomanometry, and its presence signals the need for urgent cardiac assessment and management.

Mydriasis arises from sympathetic overactivity or parasympathetic inhibition and can reflect physiologic, pharmacologic, traumatic, or neurologic causes. Early recognition and evaluation are critical for identifying ocular emergencies and preventing vision loss or neurologic compromise.

Depersonalization is a dissociative symptom in which an individual perceives the self as unreal or detached, sometimes feeling as if observing oneself from a distance; occurs in schizophrenia, depersonalization disorder, and occasionally in healthy individuals under stress.

Malaise is a nonspecific feeling of listlessness, fatigue, or general discomfort. It may develop gradually or suddenly and often precedes signs of infectious, endocrine, or neurologic disorders.

Purpura is the leakage of red blood cells from small blood vessels into the skin, subcutaneous tissue, or mucous membranes, appearing as purplish or brownish-red spots. It results from vessel damage, coagulation defects, trauma, medications, or underlying medical conditions.

Analgesia is the absence or loss of pain sensation, a neurological sign that often indicates damage to the spinothalamic tract in the spinal cord or brainstem, or to peripheral nerves. This article covers its classification, neuroanatomy, assessment, causes and management, with emphasis on spinal cord injury and protecting patients from injuries they cannot feel.

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.

Rhinorrhea is the discharge of nasal mucus, ranging from clear to purulent or bloody, caused by infections, allergies, trauma, or structural abnormalities. Its evaluation involves history, nasal examination, and occasionally imaging or lab tests to identify underlying causes and guide treatment.

Broadbent’s inverted sign is a palpable pulsations in the left posterolateral chest wall during ventricular systole, suggestive of left atrial enlargement.

Lloyd’s sign is referred loin pain triggered by deep percussion over the kidney. It is commonly associated with renal calculi.