Organ Transplant Rejection
Organ transplant rejection is a complex immunological response wherein the recipient’s immune system identifies the transplanted organ as foreign and mounts an attack against it.…
Oral Ulcers Associated with Behçet’s Disease
Behçet’s disease is a rare, chronic, multisystemic inflammatory disorder characterized by recurrent oral ulcers, genital lesions, ocular inflammation, and systemic involvement. One of the earliest…
Oral Lichen Planus
Oral lichen planus (OLP) is a chronic, autoimmune-mediated inflammatory condition that affects the mucous membranes of the mouth. Characterized by bilateral, white, lace-like lesions and,…
Oral Candidiasis
Oral candidiasis, commonly referred to as oral thrush, is a fungal infection in the oral cavity caused predominantly by Candida albicans. It manifests as white,…
Optic Neuritis
Optic neuritis is an inflammatory condition affecting the optic nerve, the structure responsible for transmitting visual information from the eye to the brain. This condition…
Opisthorchiasis
Opisthorchiasis is a significant parasitic infection caused by trematodes, primarily Opisthorchis viverrini and Opisthorchis felineus. These liver flukes inhabit the bile ducts of humans and…
Opioid-Induced Respiratory Depression
Opioid-induced respiratory depression (OIRD) is a life-threatening condition characterized by a reduced drive to breathe due to the pharmacologic effects of opioid medications on the…
Opioid-Induced Constipation (OIC)
Opioid-induced constipation (OIC) is one of the most prevalent and distressing adverse effects of opioid therapy. Unlike other opioid side effects such as sedation or…
Opioid Withdrawal Symptoms
Opioid withdrawal is a clinical syndrome that occurs when a person who is physically dependent on opioids abruptly reduces or stops usage. It is the…
Opioid Use Disorder (OUD)
Opioid Use Disorder (OUD) is a chronic, relapsing medical condition characterized by the compulsive use of opioids despite harmful consequences. It involves both physical dependence…