- Health Encyclopedia

The cardiovascular system

Stent definition and Stents in arteries

What is Stent, definition and Stents in arteries Stent is a tiny, springlike device inserted into an ARTERY to help maintain the artery’s patency after ANGIOPLASTY (a CARDIAC CATHETERIZATION procedure to clear or compress ATHEROSCLEROTIC PLAQUE from the inner walls of an artery). The stent holds pressure against the artery’s inner wall,

The Blood and Lymph System

Myelofibrosis - definition, treatment and symptoms

What is Myelofibrosis and Definition Myelofibrosis is a chronic, degenerative condition of the BONE MARROW in which fibrous tissue replaces the red BONE marrow. Researchers do not know what causes myelofibrosis, which typically develops in people between the ages of 50 and 70, but believe it is an autoimmune response from a single defective blood STEM CELL

Infectious Diseases


What is a Parasite Parasite is an organism that requires coexistence with another organism for its survival. The parasite typically draws nourishment and other needs from its host organism without contributing in return to the host’s survival. Some parasites can survive away from their hosts for limited periods of time or defined portions of their

Apolipoprotein B100 (apoB100)

What is Apolipoprotein B100 (apoB100) Apolipoprotein B100 (apoB100) is a protein on the surface of lipid molecules that directs the lipid’s route of METABOLISM. ApoB100 occurs primarily on low-density lipoprotein (LDL) molecules, the form of cholesterol with the highest risk for CORONARY ARTERY DISEASE (CAD). The normal level of apoB100 in the blood

Uterine Prolapse - symptoms and treatment

What is Uterine Prolapse Uterine Prolapse is a circumstance in which the ligaments and muscles that support the UTERUS within the abdomen weaken, allowing the uterus to sag into the VAGINA. The weakness generally occurs as a consequence of multiple pregnancies that stress them or traumatic CHILDBIRTH that causes damage to them. OBESITY increases the risk

Synovitis - Definition and Treatment

INFLAMMATION of the synovial membrane that lines the JOINT capsule of joints such as the hip and knee. Synovitis is common in RHEUMATOID ARTHRITIS, GOUT, SYSTEMIC LUPUS ERYTHEMATOSUS (SLE), and INFECTION. Generally there is PAIN, often severe, and swelling due to fluid accumulation. The SKIN over the joint is often hot to the touch and red. The doctor may

Generic Drug

Generic Drug is a DRUG that has BIOEQUIVALENCE and THERAPEUTIC EQUIVALENCE to its INNOVATOR DRUG (the first drug to receive approval for use). Generic drugs became significant in the health-care industry in the 1970s when manufacturing requirements and procedures became standardized and patents began to expire on innovator drugs, converging factors that

Renal Cyst

What is Renal Cyst An encapsulated, fluid-filled growth that occurs in the kidney. Simple renal cysts are common and nearly always benign (noncancerous). Complex renal cysts, which may contain calculi (stones) and BLOOD, may be benign or cancerous. Most renal cysts, simple or complex, do not cause symptoms. Rather, the doctor detects them during diagnostic

Sick Sinus Syndrome - Symptoms and Treatment

Sick Sinus Syndrome is a collective term for ARRHYTHMIA disorders that arise from dysfunction of the SINOATRIAL (SA) NODE and the electrical conduction network within the HEART. The SA node may stop functioning, or there may be a disruption in the pathway for the electrical impulses the SA node generates. Generally sick sinus syndrome results in bradycardia

Retrobulbar Optic Neuritis - symptoms

Retrobulbar Optic Neuritis - INFLAMMATION of the OPTIC NERVE outside the globe of the EYE, between the eye and the BRAIN. Retrobulbar optic neuritis can result from INFECTION such as MENINGITIS or ENCEPHALITIS, as a consequence of toxic exposure, and as a manifestation of MULTIPLE SCLEROSIS. Symptoms of Retrobulbar Optic Neuritis may include PAIN with

Corneal Transplantation - replacement of a diseased cornea

Corneal Transplantation - the replacement of a diseased CORNEA with a healthy donor cornea. In the United States, ophthalmologists perform more than 45,000 corneal transplantations each year; up to 90 percent of people who receive transplanted corneas experience restored vision; success depends on the reason for the transplant. Ophthalmologists may

Colostomy surgery - definition of procedure

Colostomy is a surgically created opening (stoma) through the abdominal wall through which the COLON passes fecal matter, typically accompanying surgery to remove a diseased segment of the colon. Though there are numerous medical reasons for colostomy, among the most common are COLORECTAL CANCER, traumatic injury, and severe INFLAMMATORY BOWEL DISEASE

Urticaria - acute/chronic - definition, causes, treatment and complications

What is Urticaria and Definition Urticaria is the clinical term for hives, an outbreak of wheals on the SKIN’s surface. Acute urticaria, which comes on suddenly, typically signals a HYPERSENSITIVITY REACTION. The wheals contain fluid the IMMUNE RESPONSE draws from the cells of the skin. They itch, often intensely (PRURITUS), and may appear and recede

Polycystic Kidney Disease - symptoms and treament

What is Polycystic Kidney Disease An inherited disorder in which hundreds to thousands of cysts form in the KIDNEYS as well as in other organs and structures such as the LIVER, HEART, and BRAIN. The cysts greatly enlarge and deform the kidneys. The cysts arise from the nephrons, which they destroy as they grow. Polycystic kidney disease affects about

Phosphorus supplement

Phosphorus in combination with calcium partakes in creation and maintenance of strong and healthy teeth and bones. Furthermore, it plays a key role in energy exchange. Fortunately, the possibility of Phosphorus insufficiency for people is absolutely low. Phosphorus is the second most frequent mineral in human organism. An average person has 650 g of

Peripheral Vascular Disease - symptoms and treatment

What is Peripheral Vascular Disease ATHEROSCLEROSIS that affects the peripheral arteries, notably those in the legs. ATHEROSCLEROTIC PLAQUE infiltrates the inner wall of the arteries, the intima. This causes the intima to thicken and stiffen, restricting the FLEXIBILITY of the ARTERY as well as narrowing the passage for BLOOD (arterial lumen). Peripheral

Electrocardiogram (ECG) diagnostic procedure

What is Electrocardiogram (ECG) Electrocardiogram (ECG) is a noninvasive diagnostic procedure that converts the heart’s electrical activity into patterns of signals typically recorded on paper or displayed on a screen. The ECG is the cornerstone of cardiovascular diagnosis. The normal HEART generates a consistent electrical pattern; nearly anything

Gastroparesis - causes, symptoms and treatment

Gastroparesis - slowed function of the STOMACH that delays the travel of gastric contents into the DUODENUM. Gastroparesis results from disturbances of or damage to the vagus NERVE (the tenth cranial nerve), which carries the nerve impulses that accelerate PERISTALSIS (rhythmic contractions of the gastrointestinal tract). Gastroparesis most commonly occurs

Sexual intercourse - definition

What is Sexual intercourse and Definition Sexual activity that involves penetration between sexual partners. In conventional context sexual intercourse is the insertion of a man’s erect PENIS into a woman’s VAGINA and is the primary mechanism of human reproduction. Male EJACULATION propels SEMEN into the vagina, where the SPERM it contains may

Steatorrhea - definition and symptoms

Steatorrhea - excessive excretion of fat in the stool. Steatorrheic stools are often foamy and foulsmelling, and tend to break apart and float in the toilet bowl. Steatorrhea is a symptom of numerous gastrointestinal disorders including MALABSORPTION, CELIAC DISEASE, GALLBLADDER DISEASE, PANCREATITIS, and LIVER disease. Treating the causative condition ends

Investigational New Drug (IND)

Investigational New Drug (IND) is a new DRUG in the final phases of development for which the US Food and Drug Administration (FDA) grants restricted approval for use in clinical testing, emergency treatment, or transportation across state lines. Typically the use of an IND must meet one of three requirements: The person to receive the IND enrolls in a

Sperm Donation - process and definition

What is Sperm Donation process Sperm Donation - The collection of a man’s SEMEN, which contains SPERM, for use in FERTILITY treatments. The man obtains the semen for donation through MASTURBATION to produce EJACULATION. Sperm banks (facilities that collect and store donated sperm) have varying policies for qualifying sperm donors. In general a sperm

Efficacy drug - definition

Efficacy - the ability of a DRUG to produce a predictable effect in the body. Many factors influence a drug’s efficacy, from foods and other drugs to health conditions and a person’s metabolic characteristics. An individual’s age, weight, gender, and level of activity also may affect the rate at which a drug enters, and how long it stays

Latest News & Headlines

Telomere - definition

Genetics and Molecular Medicine |

Telomere is a structure of noncoding DNA (DNA that does not convey genetic instruction) at each end of a CHROMOSOME. Telomeres are essential for chromosome duplication during cell division. They function as handles to pull the chromatids (dividing chromosomes) apart as the mother cell divides into the two new daughter cells. The process of cell division

Atherosclerosis - what is, definition, symptoms and treatment

The cardiovascular system |

What is Atherosclerosis and Definition Atherosclerosis is Accumulation of lipids and other materials (ATHEROSCLEROTIC PLAQUE) between the two layers of an artery’s inner wall, the intima. Over time the accumulations form brittle, hard deposits called atheromas that thicken the intima and the media (the middle of the arterial wall’s three

Gastrectomy surgery - definition and complications

The Gastrointestinal System |

Partial or complete surgical removal of the STOMACH, typically to treat STOMACH CANCER or uncontrollable bleeding resulting from PEPTIC ULCER DISEASE. Gastrectomy is a major OPERATION, typically an OPEN SURGERY, performed under general ANESTHESIA that requires several days to a week in the hospital and 8 to 12 weeks for total recovery and return to regular

Sexual intercourse - definition

The Reproductive System |

What is Sexual intercourse and Definition Sexual activity that involves penetration between sexual partners. In conventional context sexual intercourse is the insertion of a man’s erect PENIS into a woman’s VAGINA and is the primary mechanism of human reproduction. Male EJACULATION propels SEMEN into the vagina, where the SPERM it contains may

Bowel Atresia - definition

The Gastrointestinal System |

Bowel Atresia - a CONGENITAL ANOMALY in which there is incomplete development of the intestinal tract, typically with closures and “dead ends” that block flow through the intestines. The intestines may be entangled or intussuscepted (one segment of bowel telescopes into another), presenting grave risk for tissue death (necrosis). Nearly always

Premenstrual Syndrome (PMS) - symptoms and treatment

The Reproductive System |

What is Premenstrual Syndrome (PMS) A constellation of symptoms that occurs in a regular pattern aligned with a woman’s MENSTRUAL CYCLE. Doctors believe PMS results from the hormonal shift in the balance between ESTROGENS and PROGESTERONE that follows involution of the corpus luteum. This shift sets in motion the events that produce MENSTRUATION. PMS

Aortic Stenosis - Symptoms and Treatment

The cardiovascular system |

What is Aortic Stenosis and Definition Aortic Stenosis is narrowing of the aortic valve that restricts the flow of BLOOD from the heart’s left ventricle to the AORTA. Aortic stenosis may be congenital or acquired; in either, it tends to show symptoms later in life. Acquired aortic stenosis develops as a consequence of calcium and arterial plaque

Umbilical Cord - definition and function

The Reproductive System |

What is Umbilical Cord The entwinement of the two umbilical arteries, one umbilical VEIN, and nerves that extend from the PLACENTA to the developing FETUS during PREGNANCY. The length of the umbilical cord varies according to numerous factors. The flow of BLOOD through the umbilical arteries and vein holds the umbilical cord relatively rigid. A thick

Psoriasis - what is, types, causes, symptoms and treatment

The Integumentary System |

What is Psoriasis Psoriasis i a common, chronic SKIN condition in which the dermis produces keratinocytes at an accelerated rate. This causes immature keratinocytes, which are still soft, to reach the epidermis (the outer layer of the skin). The excess keratinocytes form lesions, typically scaly plaques, that itch (PRURITUS) or hurt. The accelerated