Disease and conditions 

Polydipsia is excessive thirst often caused by endocrine, renal, or drug-related disorders, and may be accompanied by polyuria, nocturia, and signs of dehydration. Management involves identifying the underlying cause, monitoring fluid balance, and educating patients on hydration and lifestyle adjustments.

A pleural friction rub is a coarse, grating lung sound caused by inflamed pleural surfaces rubbing together, often from pneumonia, pleurisy, pulmonary embolism, or trauma. Assessment includes auscultation, history-taking, and monitoring respiratory status, with management directed at treating the underlying cause and relieving symptoms.

Photophobia is abnormal light sensitivity, often caused by ocular disorders, trauma, systemic disease, or certain drugs. Assessment involves history-taking and careful eye examination, with management aimed at treating the underlying cause and relieving discomfort.

Visible peristaltic waves are early signs of intestinal obstruction, appearing as rolling movements across the abdomen due to increased intestinal contractions. Detection involves careful inspection and auscultation, with prompt evaluation and treatment to prevent complications like dehydration and bowel compromise.

A pericardial friction rub is a scratching or grating heart sound caused by inflamed pericardial layers, most often indicating acute pericarditis. Diagnosis relies on auscultation of its triphasic sound along the left sternal border, monitoring for complications, and treating the underlying cause.

Peau d’orange is a pitted, thickened breast skin resembling an orange peel, most often indicating advanced breast cancer but also seen in abscess or lymphatic obstruction. Evaluation includes thorough breast and axillary examination, diagnostic imaging or biopsy, and providing clear information and emotional support.

Paroxysmal nocturnal dyspnea is sudden nighttime shortness of breath that awakens a patient, usually due to left-sided heart failure and pulmonary congestion. Relief comes with sitting or standing, and management includes evaluating cardiac status, giving oxygen, and treating the underlying heart failure.

Paresthesia is an abnormal tingling, numbness, or prickling along nerve pathways, often due to neurologic, vascular, metabolic, or traumatic causes. Assessment and management focus on identifying the underlying cause and protecting areas with reduced sensation from injury.

Paralysis is the complete loss of voluntary motor function, caused by central or peripheral nervous system injury, degenerative disease, trauma, infection, or toxins, and may be acute, chronic, localized, or generalized. Management involves emergency stabilization for acute cases, thorough neurologic assessment, prevention of complications from immobility, supportive care, and addressing the underlying cause through medical, surgical, or rehabilitative interventions.

Palpitations are the conscious awareness of one’s heartbeat — felt as pounding, fluttering, racing, or skipped beats — and may stem from anxiety, stimulants, cardiac arrhythmias, valvular disease, or metabolic disorders such as thyrotoxicosis. Assessment involves history, physical exam, and ECG monitoring; urgent signs (dizziness, hypotension, irregular pulse) require oxygen, cardiac monitoring, and antiarrhythmic therapy as indicated.

A papular rash is a cluster of small, solid, raised lesions (<1 cm) that may be red, purple, or flesh-colored, arising from allergic, infectious, autoimmune, drug-related, or neoplastic conditions. Diagnosis relies on history, physical exam, and identifying underlying causes; treatment targets the etiology and may include antipruritic, antihistamine, or antibiotic therapy.

Pallor is abnormal paleness of the skin or mucous membranes caused by anemia, arterial occlusion, shock, or peripheral vasoconstriction. Its evaluation requires careful history, physical examination, and sometimes laboratory or imaging studies to identify systemic or localized causes.

Otorrhea is ear drainage that may be purulent, bloody, serous, or serosanguineous, often caused by infections, trauma, neoplasms, or external/middle ear disorders. Careful history, physical examination, and hearing assessment guide diagnosis and management, with pediatric considerations for anatomy and safety.

Ortolani’s sign is a palpable or audible click when a neonate’s hip is flexed and abducted, indicating developmental dysplasia of the hip (DDH). Early detection within the first 4–6 weeks allows effective treatment with abduction devices or casting to ensure normal hip development.

Orthostatic Hypotension (Postural Hypotension) n is a drop in blood pressure upon standing, often causing dizziness, syncope, or blurred vision, and may result from autonomic dysfunction, hypovolemia, drugs, or systemic disorders. Management includes gradual positional changes, fluid and electrolyte monitoring, medication review, and addressing underlying causes to prevent falls and complications.

Orthopnea is difficulty breathing while lying flat, often relieved by sitting upright or using pillows, commonly indicating cardiopulmonary disorders such as left-sided heart failure or COPD. Its severity and associated signs guide evaluation, treatment, and monitoring, including oxygen therapy, diuretics, and positional adjustments.

Opisthotonos is a severe, involuntary muscle spasm causing arching of the back, hyperextension of the neck, and flexion of the limbs, typically indicating meningeal irritation. It is most commonly caused by meningitis, tetanus, subarachnoid hemorrhage, or Arnold-Chiari syndrome and requires urgent neurologic assessment and supportive care.

Oliguria is defined as urine output less than 400 mL per 24 hours and is a key indicator of renal or urinary tract dysfunction, which may result from prerenal, intrarenal, or postrenal causes. It often signals potentially life-threatening conditions and requires careful evaluation of history, physical examination, laboratory tests, and close monitoring of fluid status and vital signs.

Oligomenorrhea is abnormally infrequent menstrual bleeding, usually occurring at intervals greater than 36 days, and may signal hormonal, ovarian, pituitary, thyroid, metabolic, or stress-related disorders. It is often associated with anovulation, infertility, or underlying systemic conditions and requires thorough evaluation of history, physical signs, and relevant laboratory tests.

Ocular deviation is the abnormal movement or positioning of one or both eyes, caused by ocular, neurologic, endocrine, or systemic disorders, and may signal life-threatening conditions. Early recognition through history, eye movement assessment, and neurologic evaluation is essential for timely diagnosis and management.

Nystagmus is involuntary, rhythmic oscillation of the eyes, which may be horizontal, vertical, rotary, or mixed, and classified as pendular or jerk. It indicates pathology in the brainstem, cerebellum, vestibular system, or visual pathways, and evaluation involves history, ocular motor testing, neurologic exam, and imaging, with management targeting the underlying cause and safety precautions.

Nuchal rigidity is neck stiffness that prevents flexion, often signaling meningeal irritation from meningitis or subarachnoid hemorrhage, though it can also result from cervical arthritis, encephalitis, or listeriosis.
Evaluation includes history, careful neck examination, assessment of meningeal signs, neurologic status, and imaging, while management focuses on urgent diagnosis, monitoring for increased intracranial pressure, and treating the underlying cause.

Nocturia is waking at night to pass excessive urine, often from renal, bladder, endocrine, or metabolic disorders, or from evening diuretics or high fluid intake.
Assessment includes history of frequency, volume, and triggers, physical exam (abdomen, flanks, bladder, prostate), urine studies, and management of underlying causes while limiting evening fluids and adjusting diuretic timing.

Nipple retraction is an inward pulling of the nipple below the surrounding breast surface, most often due to scarring from cancer, duct ectasia, abscess, or mastitis. Diagnosis relies on careful history, inspection in several arm positions, palpation for subareolar masses, and appropriate imaging or biopsy to rule out malignancy.

Nipple discharge is fluid release from one or both nipples that may be benign (e.g., galactorrhea, duct ectasia) or serious (e.g., intraductal papilloma, carcinoma). Careful history, breast exam, and targeted investigations (cytology, imaging, prolactin/thyroid tests, or biopsy) guide diagnosis and management.

Neck pain originates from multiple musculoskeletal, neurologic, or systemic causes, ranging from trauma to tumors. Early assessment, appropriate immobilization, and diagnostic evaluation are essential to prevent complications and guide effective treatment.

Nausea is a common symptom reflecting gastrointestinal, metabolic, infectious, neurological, or drug-related disturbances. Accurate evaluation, supportive care, and treatment of the underlying cause are critical to prevent complications such as dehydration, electrolyte imbalance, and aspiration.

Nasal flaring is an early and vital indicator of respiratory distress, caused by increased work of breathing from obstructive, parenchymal, or cardiopulmonary disorders. Prompt evaluation, airway management, and treatment of underlying causes are essential to prevent life-threatening complications.

Myoclonus consists of sudden, involuntary muscle jerks caused by hyperexcitability of cortical, subcortical, or spinal neurons and may signal neurologic disease or impending seizures. Early evaluation, seizure precautions, and management of underlying causes are essential for patient safety and optimal outcomes.

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.

Muscle weakness is a reduction in the force-generating capacity of muscles caused by neurologic, metabolic, musculoskeletal, or systemic disorders. Early recognition, careful assessment, and targeted therapy with assistive devices are essential to maintain function and prevent complications.

Muscle spasticity is excessive, involuntary muscle contraction caused by upper motor neuron lesions, often leading to stiffness, contractures, and functional limitations. Early recognition, targeted therapy, and supportive care are essential to preserve mobility and prevent complications.

Muscle spasms are sudden, painful contractions often caused by fatigue, electrolyte imbalances, or neuromuscular disorders. Early recognition, supportive care, and stretching exercises are key to symptom relief and prevention of complications.

Muscle flaccidity involves profound hypotonia and weakness, usually due to neurologic or traumatic causes, and can affect isolated or generalized muscle groups. Prompt assessment, supportive care, and rehabilitation are crucial to preserve mobility, prevent complications, and ensure patient safety.

Muscle atrophy arises from denervation, disuse, systemic disease, or aging, leading to visible wasting and functional weakness. Early recognition, proper examination, and targeted rehabilitation can prevent contractures and maintain mobility.

Murmurs are auscultatory heart sounds classified by timing, location, loudness, and quality. Accurate history, auscultation, and identification of underlying cardiac conditions are essential for diagnosis and management.

Mouth lesions are diverse, ranging from ulcers to nodules and vesicles, caused by infections, systemic diseases, drugs, trauma, or radiation. Thorough history, oral examination, and identification of underlying causes are essential for diagnosis and management.

Miosis is pupillary constriction caused by physiologic responses, drugs, ocular, or neurologic disorders. Proper evaluation of history, ocular examination, and underlying systemic conditions is essential for diagnosis and management.

Metrorrhagia is irregular uterine bleeding occurring between menstrual periods and may signal underlying gynecologic disorders. Careful history, physical examination, and investigation are essential to determine cause and guide management.

Menorrhagia is abnormally heavy or prolonged menstrual bleeding that can signal hormonal, hematologic, or uterine pathology. Early assessment, hemodynamic monitoring, and investigation of underlying causes are essential to prevent complications.