Diseases & conditions A-Z List
Diseases & Conditions A-Z List - «R»:
Restrictive cardiomyopathy refers to a group of disorders in which the heart chambers are unable to properly fill with blood because of stiffness in the heart.
In restrictive cardiomyopathy, the heart is of normal size or only slightly enlarged. However, it cannot relax normally during the t...
The retina is the light-sensitive layer of tissue at the back of the inner eye. It acts like the film in a camera -- images come through the eye's lens and are focused on the retina. The retina then converts these images to electric signals and sends them via the optic nerve to the brain.
Retinal artery occlusion
Retinal artery occlusion is a blockage in one of the small arteries that carry blood to the retina. The retina is a layer of tissue in the back of the eye that is able to sense light.
Retinal arteries may become blocked by a blood clot or fat deposits that get stuck in the arteries. These b...
Retinal detachment is a separation of the light-sensitive membrane in the back of the eye (the retina) from its supporting layers.
The retina is a transparent tissue in the back of the eye. It helps you see the images that are focused on it by the cornea and the lens. Retinal detachments are...
Retinal detachment repair
Retinal detachment repair is eye surgery to place a detached retina back into its normal position.
A detached retina means the light-sensitive tissue in the back of the eye has separated from its supporting layers.
This article describes the repair of rhegmatogenous retinal detachments -- retinal de...
Retinal vein occlusion
Retinal vein occlusion is a blockage of the small veins that carry blood away from the retina. The retina is the layer of tissue at the back of the inner eye that converts light images to nerve signals and sends them to the brain.
Retinal vein occlusion is most often caused by hardening of ...
Retinitis pigmentosa is an eye disease in which there is damage to the retina. The retina is the layer of tissue at the back of the inner eye that converts light images to nerve signals and sends them to the brain.
Retinitis pigmentosa can run in families. The disorder can be caused by a num...
Retinoblastoma is a rare, cancerous tumor of a part of the eye called the retina.
Retinoblastoma is caused by a mutation in a gene controlling cell division, causing cells to grow out of control and become cancerous.
In a little over half of the cases, this mutation develops in a child whose...
Retinopathy of prematurity
Retinopathy of prematurity (ROP) is abnormal blood vessel development in the retina of the eye in a premature infant.
The blood vessels of the retina begin to develop 3 months after conception and complete their development at the time of normal birth. If an infant is born very prematurely, ...
Retrocalcaneal bursitis is swelling (inflammation) of the fluid-filled sac (bursa) at the back of the heel bone (calcaneus).
A bursa acts as a cushion and lubricant between tendons and muscles sliding over bone. There are bursas around most large joints in the body, including the ankle.
Retrograde cystography is a detailed x-ray examination of the bladder in which contrast dye is placed into the bladder through the urethra. The urethra is the tube that carries urine from the bladder to the outside of the body.
How the Test is Performed
You will lie down on the table. A numbing med...
Retrograde ejaculation refers to the entry of semen into the bladder instead of going out through the urethra during ejaculation.
Retrograde ejaculation may be caused by prior prostate or urethral surgery, diabetes, some medications, including some drugs used to treat hypertension (high bloo...
Retroperitoneal fibrosis is a rare disorder in which the tubes (ureters) that carry urine from the kidneys to the bladder are blocked by a mass in the area behind the stomach and intestines.
Retroperitoneal fibrosis is a rare disorder that occurs when extra fibrous tissue forms in the area b...
Retroperitoneal inflammation is swelling that occurs in the retroperitoneal space. The retroperitoneal space is in front of the lower back and behind the abdominal lining (peritoneum). Organs in this space include the pancreas, spleen, and kidneys.
Retropharyngeal abscess is a collection of pus in the tissues in the back of the throat. It is a potentially life-threatening medical condition.
See also: Peritonsillar abscess
Retropharyngeal abscess generally affects children under age 5, but it can occur at any age.
Infected material (pu...