Introduction Bipolar disorder is a chronic psychiatric condition characterized by recurrent mood swings that alternate between periods of elevated affect (mania or hypomania) and episodes of marked sadness or anhedonia (depression). The diagnostic classification encompasses several subtypes, including Bipolar I, Bipolar II, cyclothymic disorder, and rapid‑cycling bipolar disorder, each distinguished by the intensity, duration, and…
Introduction Definition and Overview Depression is a complex neuropsychiatric disorder characterized by persistent low mood, anhedonia, and functional impairment. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM‑5) identifies several diagnostic specifiers and subtypes, yet the core clinical picture remains consistent across populations. The disorder imposes a substantial burden on healthcare systems worldwide,…
Introduction Definition and Overview Anxiety disorders encompass a spectrum of conditions characterized by excessive, persistent fear or worry that interferes with daily functioning. The Diagnostic and Statistical Manual of Mental Disorders (DSM‑5) identifies generalized anxiety disorder, panic disorder, social anxiety disorder, specific phobias, and others within this category. Symptoms frequently include physiological arousal, cognitive distortions,…
Introduction The chronic infections caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) represent major global public health concerns, contributing significantly to morbidity and mortality associated with liver disease, cirrhosis, and hepatocellular carcinoma. HBV is a partially double‑stranded DNA virus that infects hepatocytes and establishes persistent infection through integration of covalently closed circular…
References Bennett JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia: Elsevier; 2019. Bennett PN, Brown MJ, Sharma P. Clinical Pharmacology. 12th ed. Edinburgh: Elsevier; 2019. Waller DG, Sampson AP. Medical Pharmacology and Therapeutics. 6th ed. Edinburgh: Elsevier; 2022. Feather A, Randall D, Waterhouse M. Kumar…
Introduction Shingles, also known as herpes zoster, is a reactivation of latent varicella‑zoster virus (VZV) that manifests as a painful dermatomal rash. The clinical picture is dominated by vesicular lesions that follow a distinct dermatome, often accompanied by significant neuropathic pain. The disease burden is substantial, affecting millions worldwide each year, with prevalence increasing in…
Introduction Lyme disease represents a vector‑borne zoonosis caused primarily by the spirochete Borrelia burgdorferi in North America and by related genospecies in Europe and Asia. The disease is transmitted to humans through the bite of infected Ixodes ticks, with the third stage of the tick cycle being the most clinically relevant for human infection. Over…
Introduction Lyme disease is a vector‑borne zoonotic infection caused by the spirochete Borrelia burgdorferi and related species. It is transmitted primarily through the bite of infected Ixodes ticks, which are widely distributed across temperate regions of North America, Europe, and Asia. The disease presents with a variable spectrum of manifestations, ranging from an initial erythema migrans rash…
Introduction Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide, despite the availability of effective pharmacotherapies. The disease, caused by the bacterium Mycobacterium tuberculosis, primarily affects the lungs but can disseminate to extra‑pulmonary sites, producing a spectrum of clinical manifestations. The enduring public health challenge stems from its latent phase, variable presentation, and…
Introduction Streptococcal pharyngitis, commonly referred to as strep throat, represents a significant public health concern due to its prevalence, potential complications, and capacity for rapid spread within community settings. The condition is caused primarily by group A β‑hemolytic streptococci (GAS) of the species Streptococcus pyogenes, which colonize the oropharynx and nasopharynx of susceptible individuals. Historically,…