Rhabdomyosarcoma is a rare and aggressive type of cancer that develops from immature muscle cells. Although it arises from cells that normally form skeletal muscle, the tumor can occur in many parts of the body, including areas where muscle tissue is minimal or absent. It most commonly affects children and adolescents and requires prompt medical treatment for the best outcomes. …
Reye’s syndrome is a rare but serious condition that causes sudden swelling of the liver and brain. It most commonly affects children and teenagers recovering from a viral infection such as influenza or chickenpox. The condition has been strongly associated with the use of aspirin and aspirin-containing medications during viral illnesses. Reye’s syndrome is a medical emergency and requires immediate …
Rett syndrome is a rare genetic neurological disorder that primarily affects girls and leads to severe impairments in brain development. Children with Rett syndrome typically appear to develop normally during the first months of life, followed by a period of developmental regression. The condition affects movement, communication, and cognitive abilities and is caused by mutations in the MECP2 gene. Symptoms …
Retrograde ejaculation is a condition in which semen flows backward into the bladder instead of exiting through the penis during ejaculation. As a result, little or no semen is released despite the sensation of orgasm. This condition is not usually harmful to overall health but can affect male fertility and cause emotional distress. It is most commonly seen in adult …
Retinal diseases are a group of eye conditions that affect the retina, the light-sensitive layer at the back of the eye responsible for converting light into visual signals. Damage to the retina can lead to vision impairment or blindness if not diagnosed and treated promptly. Retinal diseases can be caused by aging, genetics, systemic conditions like diabetes, trauma, or infections. …
Restless legs syndrome (RLS) is a neurological disorder characterized by an uncontrollable urge to move the legs, usually accompanied by uncomfortable sensations such as tingling, crawling, or itching. Symptoms often worsen during periods of rest or inactivity, particularly in the evening or at night, and may interfere with sleep. RLS can affect people of all ages but is more common …
Respiratory syncytial virus (RSV) is a common viral infection that primarily affects the respiratory tract, particularly in infants, young children, and older adults. It is a leading cause of bronchiolitis and pneumonia in children under two years old. RSV spreads easily through respiratory droplets and direct contact, and infections can range from mild cold-like symptoms to severe respiratory illness requiring …
Residual limb pain is discomfort or pain felt in the remaining part of a limb after amputation. It differs from phantom limb pain, which is pain perceived in the part of the limb that is no longer present. Residual limb pain can interfere with healing, prosthetic use, and overall quality of life. The pain may be temporary during the healing …
Renal artery stenosis is a condition in which one or both renal arteries become narrowed, reducing blood flow to the kidneys. This decreased blood supply can impair kidney function and lead to secondary high blood pressure. Renal artery stenosis is most commonly caused by atherosclerosis, particularly in older adults, but it can also result from fibromuscular dysplasia in younger individuals. …
REM sleep behavior disorder is a sleep-related condition in which the normal muscle paralysis that occurs during rapid eye movement sleep is absent or incomplete. As a result, individuals physically act out their dreams, which are often vivid and intense. These behaviors can include talking, shouting, punching, kicking, or jumping from bed. REM sleep behavior disorder most commonly affects older …