Romano-Ward syndrome is an inherited heart (cardiac) disorder characterized by abnormalities affecting the electrical system of the heart. The severity of Romano-Ward syndrome varies greatly from case to case. Some individuals may have no apparent...

A balance disorder is a condition that makes you feel unsteady or dizzy, as if you are moving, spinning, or floating, even though you are standing still or lying down. Balance disorders can be caused by certain health conditions, medications, or a...

The botulism neurotoxin is one of the most potent, lethal substances known. Botulism is a disease caused by this neurotoxin (specifically A, B, E, or F type neurotoxin). The neurotoxin is produced by bacteria called Clostr...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

Creutzfeldt-Jakob disease (CJD) is a rare, degenerative, invariably fatal brain disorder. It affects about one person in every one million people per year worldwide; in the United States there are about 200 cases per year. CJD usually appears in l...

Type 2 diabetes is an impairment in the way the body regulates and uses sugar (g...

Eales Disease is a rare disorder of sight that appears as an inflammation and white haze around the outercoat of the veins in the retina. The disorder is most prevalent among young males and normally affects both eyes. Usually, vision is suddenly ...

Polycythemia vera is a rare, chronic disorder involving the overproduction of blood cells in the bone marrow (myeloproliferation). The overproduction of red blood cells is most dramatic, but the production of white blood cells and platelets are al...

Cryptococcosis is caused by a fungus known as Cryptococcosis neoformans. The infection may be spread to humans through contact with pigeon droppings or unwashed raw fruit. Contact with an infected individual may also spread the infection. Individu...

Glaucoma is a disease that is often associated with elevated intraocular pressure, in which damage to the eye (optic) nerve can lead to loss of vision and even blindness. Glaucoma is the leading cause of irreversible blindness in th...

Hydrocephalus is a condition characterized by excessive accumulation of fluid in the brain. Hydrocephalus may be congenital or acquired. Communicating hydrocephalus occurs when cerebrospinal fluid (CSF) can still flow amon...

Insulin is a hormone that is produced by the beta cells of the pancreas. These cells are scattered throughout the pancreas in small clusters known as the islets of Langerhans. The insulin produced is released into the blood stream and travels thro...

General DiscussionRomano-Ward syndrome is an inherited heart (cardiac) disorder characterized by abnormalities affecting the electrical system of the heart. The severity of Romano-Ward syndrome varies greatly from case to case. Some indiv...

Diabetic Retinopathy is a complication of diabetes and a disorder of the light sensitive tissue of the eye (the retina). This condition is characterized by destructive changes in the blood vessels of the retina, which, if left unchecked, may lead ...

Renal glycosuria, also known as renal glucosuria, is a rare condition in which the simple sugar glucose is eliminated (excreted) in the urine despite normal or low blood glucose levels. With normal kidney (renal) function, glucose is excreted in t...

Progressive supranuclear palsy, or PSP, is a rare neurodegenerative disease that is often misdiagnosed as Parkinson's disease because it carries similar symptoms. Because of its rarity, PSP is mostly unknown by the general public....

Pineal cysts are benign (non-cancerous) fluid-filled sacs located in the region of the brain that contains the pineal gland. Small pineal cysts (.5 cm or smaller) are common occurrences, often found incidentally on routine neurological exams. Smal...

Spinal headaches are a fairly common complication in those who undergo a spinal tap (lumbar puncture) or spinal anesthesia. Both procedures require a puncture of the membrane that surrounds the spinal cord and, in the lower spine, the lumbar and s...

Creutzfeldt-Jakob disease (CJD) is an extremely rare degenerative brain disorder (i.e., spongiform encephalopathy) characterized by sudden development of rapidly progressive neurological and neuromuscular symptoms. With symptom onset, affected ind...

Introduction The superior vena cava is a large vein located in the upper chest, which collects blood from the head and arms and delivers it back to the right atrium of the heart. If this vein is compressed by outside structures, or if a th...

Cervical dystonia, also known as spasmodic torticollis, is a rare neurological disorder characterized by involuntary muscle contractions in the neck that cause abnormal movements and postures of the neck and head. In some cases, these abnormal con...

Toxoplasmosis is an infection caused by a single-celled parasite called Toxoplasma gondii. The infection is most commonly acquired from contact with cats and their feces or with raw or undercooked meat. The U.S. Centers for Disease Control...

Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition in which the pancreas produces little or no insulin. Insulin is a hormone needed to allow sugar (glucose) to enter cells to produce energy. ...

Uveitis is inflammation of the 'uvea' of the eye. The uvea is made up of three parts. The first part is the iris, which is the colored ring of tissue you can see in the mirror. The dark hole in the middle of the iris is the pupil. The second and t...

Nephrogenic diabetes insipidus (NDI) is a rare kidney disorder that may be inherited or acquired. NDI is not related to the more common diabetes mellitus (sugar diabetes), in which the body does not produce or properly use insulin. NDI is a distin...

Best vitelliform macular dystrophy is an autosomal dominant genetic form of macular degeneration that usually begins in childhood or adolescence and slowly progresses to affect central vision. The age of onset and severity of vision loss are highl...