Pathologic myopia, also known as degenerative or malignant myopia, is a severe form of high myopia characterized by progressive and structural changes to the posterior segment of the eye. These changes include excessive axial elongation, thinning of the retina and choroid, posterior staphyloma, and macular atrophy, all of which contribute to irreversible visual impairment. Defined
Patent ductus arteriosus (PDA) is a congenital cardiac anomaly in which the ductus arteriosus—a fetal blood vessel connecting the pulmonary artery to the aorta—fails to close after birth. This persistent opening leads to abnormal circulation between the systemic and pulmonary arteries, resulting in increased workload on the heart and lungs. During fetal development, the ductus
Partial epilepsy, also referred to as focal epilepsy, originates in a specific region of the cerebral cortex. Seizures can remain localized or evolve into generalized seizures. When first-line antiepileptic drugs (AEDs) fail to provide sufficient control, adjunctive treatments—used in combination with baseline therapy—offer critical support in reducing seizure frequency and improving quality of life. Adjunctive
Partial central diabetes insipidus is a subtype of central diabetes insipidus characterized by incomplete deficiency of arginine vasopressin (AVP), also known as antidiuretic hormone (ADH). Unlike complete CDI, where AVP secretion is nearly absent, the partial form involves a measurable but insufficient level of AVP production, leading to impaired water reabsorption and mild to moderate
Paroxysmal supraventricular tachycardia (PSVT) refers to a group of arrhythmias characterized by sudden-onset episodes of rapid heart rate originating above the ventricles. These arrhythmias can abruptly begin and end, with heart rates often ranging between 150 and 250 beats per minute. PSVT episodes can occur in structurally normal hearts and are frequently observed in young
Paroxysmal atrial tachycardia (PAT) is a type of supraventricular tachycardia (SVT) characterized by sudden, episodic bursts of rapid heart rate originating from an ectopic focus in the atria, outside the sinoatrial node. These episodes occur abruptly and terminate just as suddenly, often lasting from seconds to several hours. PAT is typically non-life-threatening but may cause
Paroxysmal atrial flutter is a type of supraventricular tachycardia marked by intermittent episodes of rapid and regular atrial contractions. Unlike persistent or chronic atrial flutter, paroxysmal forms are self-limited, lasting for minutes to several hours, and often terminate spontaneously. This condition poses significant clinical relevance due to its potential progression to atrial fibrillation and increased
Paroxysmal atrial fibrillation is a subtype of atrial fibrillation characterized by sudden and recurrent episodes of irregular heart rhythm that typically resolve on their own within 7 days, often within 24 hours. These episodes can occur sporadically and without warning, potentially progressing into more persistent or permanent forms of AFib if not effectively managed. It
Paronychia is an infection or inflammation of the periungual tissue, which surrounds the fingernails or toenails. It is one of the most common infections affecting the hand and is often caused by bacterial, fungal, or mixed pathogens. Paronychia can be acute or chronic and may lead to significant pain, swelling, and functional limitations if not
Parkinsonism refers to a group of neurological disorders characterized by symptoms similar to those of Parkinson’s disease. These include bradykinesia, rigidity, resting tremor, and postural instability. While Parkinson’s disease is the most well-known cause, other neurodegenerative and secondary conditions may also lead to parkinsonian features. Parkinsonism is not a diagnosis but a clinical syndrome, and