Definition Inflammation of the vagina and vulva most often caused by a bacterial, fungal, or parasitic infection. Description Vulvovaginitis, vulvitis, and vaginitis are general terms that refer to the inflammation of the vagina and/or vulva (the external genital organs of a woman). These conditions can be caused by bacterial, fungal, or parasitic infections. Also, vulvovaginitis can...

Definition Vulvodynia is chronic pain of the vulva, the external or visible region of the female genitalia, in the absence of vulvar or vaginal infection or skin disease. Description As with other types of chronic pain, vulvodynia can have a significant impact on the quality of life. The disease may interfere with daily activities including sitting, walking, physical exercise, and...

Definition Vulvar cancer refers to an abnormal, cancerous growth in the external female genitalia. Description Vulvar cancer is a rare disease that occurs mainly in elderly women. The vulva refers to the external female genitalia, which includes the labia, the opening of the vagina, the clitoris, and the space between the vagina and anus (perineum). There are...

Definition Von Willebrand disease is caused by a deficiency or an abnormality in a protein called vonWillebrand factor and is characterized by prolonged bleeding. Description The Finnish physician Erik von Willebrand was the first to describe von Willebrand disease(VWD). In 1926 Dr. von Willebrand noticed that many male...

Definition Vocal cord paralysis is the inability to move the vocal cords and the resulting loss of vocal cord function. Description The vocal cords are a pair of tough, fibrous bands that lie across the air column in the middle of the voice box. They assist three functions: breathing, swallowing, and speaking. When vocal cords vibrate, they produce sound, allowing us to speak. Vocal cords...

Definition Vocal cord nodules and polyps are noncancerous growths on the vocal cords that affect the voice. Description The vocal cords, located in the voice box in the middle of the neck, are two tough, fibrous bands that vibrate to produce sound. They are covered with a layer of tissue that is similar to skin. With use, this layer thickens. With heavy use, the thickening...

Definition Vitrectomy is the surgical removal of the vitreous (transparent gel that fills the eye from the iris to the retina). Purpose The bulk of the contents of the eyeball is a clear jelly-like substance that is susceptible to several afflictions that impair vision by damaging its transparency. ·         Infections ·        ...

Definition Vitiligo is a condition in which a loss of cells that give color to the skin (melanocytes) results in smooth, white patches in the midst of normally pigmented skin. Description Vitiligo is a common, often inherited disorder characterized by areas of well-defined, milky white skin. People with vitiligo may have eye abnormalities and also have...

Definition Vitamins are organic components in food that are needed in very small amounts for growth and for maintaining good health. The vitamins include vitamins D, E, A, and K (fat-soluble vitamins), and folate (folic acid ), vitamin B12, biotin, vitamin B6, niacin, thiamin, riboflavin, pantothenic acid, and vitamin C (ascorbic acid) (water-soluble vitamins). Vitamins are...

Definition Vitamin toxicity is a condition in which a person develops symptoms as side effects from taking massive doses of vitamins. Vitamins vary in the amounts that are required to cause toxicity and in the specific symptoms that result. Vitamin toxicity, which is also called hypervitaminosis or vitamin poisoning, is...

Definition Vitamins are small organic molecules that are necessary for many biochemical reactions in the body. For example, many vitamins participate as cofactors in enzyme reactions within the cells. They must be obtained through diet, microorganisms in the gut or sunlight since humans cannot synthesize them. Vitamin tests measure the levels of certain vitamins in...

Definition Vitamin K deficiency exists when chronic failure to eat sufficient amounts of vitamin K results in a tendency for spontaneous bleeding or in prolonged and excessive bleeding with trauma or injury.Vitamin K deficiency occurs also in newborn infants, as well as in people treated with certain antibiotics. The protein in the body most...

Definition Vitamin E deficiency is a very rare problem that results in damage to nerves. When vitamin E deficiency does occur, it strikes people with diseases that prevent the absorption of dietary fats and fat-soluble nutrients. Since vitamin E is a fat-soluble vitamin, it has some of the properties of fat. Description The recommended dietary...

Definition Vitamin D deficiency exists when the concentration of 25-hydroxy-vitamin D (25-OH-D) in the blood serum occurs at 12 ng/ml (nanograms / milliliter), or less. The normal concentration of 25-hydroxy-vitamin D in the blood serum is 25-50 ng/ml. When vitamin D deficiency continues for many months in growing children, the disease...

Definition Vitamin B6 is used by the body as a catalyst in reactions that involve amino acids. Vitamin B6deficiency is rare, since most foods eaten contain the vitamin. Description Vitamin B6 is a water-soluble vitamin. The recommended dietary allowance (RDA) for vitamin B6 is 2.0 mg/day for the adult man and 1.6 mg/day for the adult woman. Vitamin B6 in the diet generally...

Definition Vitamin A deficiency exists when the chronic failure to eat sufficient amounts of vitamin A or beta-carotene results in levels of blood-serum vitamin A that are below a defined range. Beta-carotene is a form of pre-vitamin A, which is readily converted to vitamin A in the body. Night blindness is the...

Definition Total blindness is the inability to tell light from dark, or the total inability to see. Visual impairment or low vision is a severe reduction in vision that cannot be corrected with standard glasses or contact lenses and reduces a person's ability to function at certain or all tasks. Legal blindness (which is actually a severe visual impairment)...

Definition Vision training, also known as vision therapy or orthoptics, consists of a variety of programs to enhance visual performance. It includes treatments for focusing, binocularity, and eye movement problems. Vision training is generally provided by an optometrist (O.D.). Purpose While visual acuity refers to how clearly each eye can see, vision training...

Definition Vibriosis is a disease caused by an infection with bacteria of the Vibrio genus, most commonlyVibrio parahemolyticus or Vibrio vulnificus. Vibrio bacteria cause diarrhea, skin infections, and/or blood infections. The diarrhea-causing Vibrio parahemolyticus is a relatively harmless infection, butVibrio vulnificus infection,...

Definition Vesicoureteral reflux (VUR) refers to a condition in which urine flows from the bladder, back up the ureter, and back into the kidneys. Description The normal flow of urine begins in the collecting system of each kidney. Urine then flows out of each kidney and into a tube called the ureter. Each ureter leads into the bladder, where the urine collects until it is passed...

Definition Ventricular tachycardia (V-tach) is a rapid heart beat that originates in one of the lower chambers (the ventricles) of the heart. To be classified as tachycardia, the heart rate is usually at least 100 beats per minute. Description A rapid heart rate can originate in either the left or right ventricle. Ventricular tachycardia which lasts more than 30 seconds is referred...

Definition Ventricular shunt is a surgical procedure in which a tube is placed in one of the fluid-filled chambers inside the brain (ventricles). The fluid around the brain and the spinal column is called the cerebrospinal fluid. When infection or disease causes an excess of this cerebrospinal fluid in the ventricles, the shunt is placed to drain it and thereby relieve...

Definition A ventricular septal defect is a hole in the wall of the heart (septum) that separates the left lower chamber (left ventricle) from the right lower chamber (right ventricle). The hole allows blood to flow from the left ventricle to the right ventricle instead of entering the aorta for distribution throughout the body. Ventricular septal defect is...

Definition Ventricular fibrillation is a very rapid, uncoordinated, ineffective series of contractions throughout the lower chambers of the heart. Unless stopped, these chaotic impulses are fatal. Description When the ventricles begin to quiver and do not employ coordinated contractions, the heart is said to be fibrillating. In this condition the ventricles cannot pump blood from the heart. Ventricularfibrillation (V-fib)...

Definition A ventricular ectopic beat (VEB) is an extra heart-beat originating in the lower chamber of the heart. This beat, also called a premature ventricular contraction (PVC), occurs before the beat triggered by the heart's normal function. Description Ventricular ectopic beats are common and do not indicate a problem in people without heart...

Definition A ventricular assist device (VAD) is a mechanical pump used for temporary blood circulation support. It decreases the workload of the heart while maintaining adequate flow and blood pressure. Purpose A VAD is a temporary life-sustaining device. VADs can replace the left ventricle (LVAD), the right ventricle (RVAD), or both ventricles (BIVAD). They are used when...

Definition Ventricular aneurysm is a complication of a heart attack (myocardial infarction). It is a ballooning of a section of a blood vessel in the heart that first appears several days or weeks after an acute myocardial infarction. Description A myocardial infarction occurs when a section of the heart wall is deprived of blood and dies (undergoes necrosis,...

Definition Venous insufficiency is described as abnormal blood flow through veins that can cause local damage, damage to affected legs, or death. Description Syndromes related to venous insufficiency are caused by valve incompetence. Venousinsufficiency is a chronic (long term) condition. The number of new and existing cases is dependent on age and...

Definition Venous access introduces a needle into a vein, usually for the purpose of withdrawing blood or administering medication. Purpose Venous access is necessary for fluid administration, medication administration, and obtaining blood for chemical analysis. Sites for access include veins located in the peripheral arms or legs, scalp, neck, and bone. Venous access in...

Definition Venography is an x-ray test that provides an image of the leg veins after a contrast dye is injected into a vein in the patient's foot. Purpose Venography is primarily performed to diagnose deep vein thrombosis (a condition that can lead to pulmonary embolism ). It is the standard procedure used to detect this type of disorder. Venography...

Definition A vena cava filter is a device inserted into a major vein to prevent a blood clot from entering the lungs. Purpose The purpose of a vena cava filter is to prevent a blood clot from potentially traveling to the lungs. A thrombus clot traveling to the lungs is called a pulmonary embolism (PE). A thrombus...

Definition Velopharyngeal insufficiency is the improper closing of the velopharyngeal sphincter (soft palate muscle) during speech characterized by an acute nasal quality of the voice. Description At the back of the mouth is a circle of structures that include the tonsils, the tongue, and the palate. During speech, this apparatus must close off the nose for proper...

Definition A coma-like state characterized by open eyes and the appearance of wakefulness is defined as vegetative. Description The vegetative state is a chronic or long-term condition. This condition differs from a persistent vegetative state (PVS, a state of coma that lacks both awareness and wakefulness) since...

Definition Vasodilators are medicines that act directly on muscles in blood vessel walls to make blood vessels widen (dilate). Purpose Vasodilators are used to treat high blood pressure (hypertension ). By widening the arteries, these drugs allow blood to flow through more easily, reducing blood pressure. Controlling high blood pressure is important because the condition...

Definition A vasectomy is a surgical procedure performed on adult males in which the vasa deferentia (tubes that carry sperm from the testicles to the seminal vesicles) are cut, tied, cauterized (burned or seared), or otherwise interrupted. The semen no longer contains sperm after the tubes are cut, so conception cannot occur. The testicles continue to produce sperm, but the...

Definition Vasculitis refers to a varied group of disorders which all share a common underlying problem of inflammation of a blood vessel or blood vessels. The inflammation may affect any size blood vessel, anywhere in the body. It may affect either arteries and/or veins. The inflammation may be focal, meaning that it affects a single location within a vessel; or it may be...

Definition Varicose veins are dilated, tortuous, elongated superficial veins that are usually seen in the legs. Description Varicose veins, also called varicosities, are seen most often in the legs, although they can be found in other parts of the body. Most often, they appear as lumpy, winding vessels just below the surface of the skin. There...

Definition Valvular heart disease refers to several disorders and diseases of the heart valves, which are the tissue flaps that regulate the flow of blood through the chambers of the heart. Description The human heart consists of four chambers—two upper chambers (the atria) and two lower chambers (the ventricles) that are responsible for pumping...

Definition The Valsalva maneuver is performed by attempting to forcibly exhale while keeping the mouth and nose closed. It is used as a diagnostic tool to evaluate the condition of the heart and is sometimes done as a treatment to correct abnormal heart rhythms or relieve chest pain. Purpose The Valsalva maneuver is used with patients who...

Definition Vagotomy is the surgical cutting of the vagus nerve to reduce acid secretion in the stomach. Purpose The vagus nerve splits into branches that go to different parts of the stomach. Stimulation from these branches causes the stomach to produce acid. Too much stomach acid leads to ulcers that may eventually bleed and create an emergency situation. Vagotomy is...

Definition Pain in the vaginal canal is usually associated with an underlying medical and/or psychological condition. Description Vaginal pain is experienced usually during vaginal manipulation or sexual intercourse. Approximately 50-85% of the causes are due to organic (medical) conditions. However, it is typical for the medical condition to be compounded...

Definition Vaccination introduces a vaccine into the body to produce immunity and prevent specific diseases. Description Many diseases that once caused widespread illness, disability, and death are now prevented by vaccines in developed countries. Vaccines are medicines that contain weakened or dead bacteria or viruses. When a child receives a vaccine, his or her immune system responds...

In about 75 percent of women there develops a tendency to nausea and vomiting, usually in the mornings during the fifth to the sixteenth weeks of pregnancy. The symptom is most noticeable with the first pregnancy. The cause is not well-understood. In about one case in 200 the symptom is severe, requiring hospital care.  

Varicose veins are veins which have become lengthened, enlarged, and "knotty" in appearance. The change occurs commonly in the surface veins of the legs. As such a vein lengthens, it becomes tortuous. Varicose veins may be caused by any factor which retards the flow of blood through the veins involved. Varicose veins occur more commonly in some families than in others. Pressure against the pelvic...