Definition Oxygen/ozone therapy is a term that describes a number of different practices in which oxygen,ozone, or hydrogen peroxide are administered via gas or water to kill disease microorganisms, improve cellular function, and promote the healing of damaged tissues. The rationale behind bio-oxidative therapies, as they are sometimes known, is the notion that as long as the body's needs for antioxidants are...

Definition Over hydration, also called water excess or water intoxication, is a condition in which the body contains too much water. Description Over hydration occurs when the body takes in more water than it excretes and its normal sodium level is diluted. This can result in digestive problems, behavioral changes, brain damage, seizures, or coma. An adult whose heart, kidneys, and pituitary gland...

Definition Overactive bladder is the leakage of large amounts of urine at unexpected times, including during sleep. Description People who lose urine for no apparent reason while suddenly feeling the need or urge to urinate may have overactive bladder. The condition effects 17 million Americans. The most common cause of over active bladder is inappropriate bladder contractions....

Definition Ovarian torsion is the twisting of the ovary due to the influence of another condition or disease. This results in extreme lower abdominal pain. Description Ovarian torsion occurs infrequently only in females. In can occur in women of all ages, but most women that experience this are younger. Approximately 70-75% of cases occur in women under 30 years old. About 20% of all...

Definition Ovarian cysts are sacs containing fluid or semisolid material that develop in or on the surface of an ovary. Description Ovarian cysts are common and the vast majority are harmless. Because they cause symptoms that may be the same as ovarian tumors that may be cancerous, ovarian cysts should always be checked out. The most common types of ovarian cysts are...

Definition Ovarian cancer is cancer of the ovaries, the egg-releasing and hormone-producing organs of the female reproductive tract. Cancerous, or malignant, cells divide and multiply in an abnormal fashion. Description The ovaries are small, almond-shaped organs, located in the pelvic region, one on either side of the uterus. When...

Definition Ototoxicity is damage to the hearing or balance functions of the ear by drugs or chemicals. Description Ototoxicity is drug or chemical damage to the inner ear. This section of the ear contains both the hearing mechanism and the vestibulocochlear nerve, the nerve that sends hearing and balance information to the brain. Because of this, ototoxic drugs may cause lack of hearing, and loss of...

Definition Otosclerosis is an excessive growth in the bones of the middle ear which interferes with the transmission of sound. Description The middle ear consists of the eardrum and a chamber which contains three bones called the hammer, the anvil, and the stirrup (or stapes). Sound waves passing through the ear cause the ear drum to vibrate. This vibration is transmitted to the inner ear by the three bones....

Definition Otitis media is an infection of the middle ear, which is located behind the eardrum. There are two main types of otitis media. In the first, called acute otitis media (AOM), parts of the ear are infected and swollen, and fluid and mucus are trapped inside the ear. AOM can be quite painful. In the second type, called otitis media with effusion (fluid),...

Definition Otitis externa refers to an infection of the ear canal (outer ear), the tube leading from the outside opening of the ear in towards the ear drum. The infection usually develops in children and adolescents whose ears are exposed to persistent, excessive moisture. Description The external ear canal is a tube approximately 1 in (2.5 cm) in length that runs from the outside opening of the ear...

Definition A surgical procedure creating an opening in the body for the discharge of body wastes. Purpose Certain diseases of the bowel or urinary tract involve removing all or part of the intestine or bladder. This creates a need for an alternate way for feces or urine to leave the body. An opening is surgically created in...

Definition The word osteoporosis literally means "porous bones." It occurs when bones lose anexcessive amount of their protein and mineral content, particularly calcium. Over time, bone mass, and therefore bone strength, is decreased. As a result, bones become fragile and break easily. Even a sneeze...

Definition Osteopetrosis (plural osteopetroses) is a rare inherited disorder that makes bones increase in both size (mass) and fragility. It is a potentially fatal condition that can deform bone structure and distort the appearance. Osteopetrosis is also called chalk bones, ivory bones, or marble bones. Description In healthy individuals, bones are constantly being broken down (resorption) by cells called...

Definition Osteopathy is a system and philosophy of health care that separated from traditional (allopathic) medical practice about a century ago. It places emphasis on the musculoskeletal system, hence the name—osteo refers to bone and path refers to disease. Osteopaths also believe strongly in the healing power of the body and do their best to facilitate that strength. During this century, the disciplines...

Definition Osteomyelitis refers to a bone infection, almost always caused by a bacteria. Over time, the result can be destruction of the bone itself. Description Bone infections may occur at any age. Certain conditions increase the risk of developing such an infection, including sickle cell anemia, injury, the presence of a foreign body (such as a bullet or a screw placed to hold together a broken bone),...

Definition Osteogenesis imperfecta (OI) is a group of genetic diseases of collagen in which the bones are formed improperly, making them fragile and prone to breaking. Description Collagen is a fibrous protein material. It serves as the structural foundation of skin, bone, cartilage, and ligaments. In osteogenesis imperfecta, the collagen produced is abnormal and disorganized. This results...

Definition The term osteochondroses refers to a group of diseases of children and adolescents in which localized tissue death (necrosis) occurs, usually followed by full regeneration of healthy bone tissue. The singular term is osteochondrosis. Description During the years of rapid bone growth, blood supply to the growing ends of bones (epiphyses) may become insufficient resulting in necrotic bone,...

Definition Osteoarthritis (OA), which is also known as osteoarthrosis or degenerative joint disease(DJD), is a progressive disorder of the joints caused by gradual loss of cartilage and resulting in the development of bony spurs and cysts at the margins of the joints. The name osteoarthritis comes from three Greek words meaning bone, joint,...

Definition Orthostatic hypotension refers to a reduction of blood pressure (systolic blood pressure that occurs when the heart contracts) of at lest 20 mmHg or a diastolic pressure (pressure when the heart muscle relaxes) of at least 10 mmHg within three minutes of standing. Description Orthostatic hypotension is a decrease of blood pressure when standing, due to changes in the blood pressure...

Definition Orthopedic (sometimes spelled orthopedic) surgery is an operation performed by a medical specialist such as an orthopedist or orthopedic surgeon, who is trained to assess and treat problems that develop in the bones, joints, and ligaments of the human body.  Purpose Orthopedic surgery addresses and attempts to correct problems that arise in the skeleton...

Definition Orchitis is an inflammation of the testis, accompanied by swelling, pain, fever, and a sensation of heaviness in the affected area. Description Viral mumps is the most common cause of orchitis. Bacterial infections associated with the disorder are tuberculosis, syphilis, gonorrhea, and chlamydia. A mechanical injury to the groin area may also cause orchitis....

Definition Periorbital cellulitis is an inflammation and infection of the eyelid and the skin surrounding the eye.Orbital cellulitis affects the eye socket (orbit) as well as the skin closest to it. Description Inside the eyelid is a septum. The septum divides the eyelid into outer and inner areas. This orbital septum helps prevent the spread of infection to the eye socket. Periorbital and orbital cellulitis...

Definition Oral hygiene is the practice of keeping the mouth clean and healthy by brushing and flossing to prevent tooth decay and gum disease. Purpose The purpose of oral hygiene is to prevent the buildup of plaque, the sticky film of bacteria and food that forms on the teeth. Plaque adheres to the crevices and fissures of the teeth and generates acids that, when not removed...

Definition Oral contraceptives are medicines taken by mouth to help prevent pregnancy. They are also known as the Pill, OCs, or birth control pills. Purpose Oral contraceptives, also known as birth control pills, contain artificially made forms oftwo hormones produced naturally in the body. These hormones, estrogen and...

Definition Optic neuritis is a vision disorder characterized by inflammation of the optic nerve. Description Optic neuritis occurs when the optic nerve, the pathway that transmits visual information to the brain, becomes inflamed and the myelin sheath that surrounds the nerve is destroyed (a process known as demyelination). It typically occurs in one eye at a time (70%),...

Definition Optic atrophy can be defined as damage to the optic nerve resulting in a degeneration or destruction of the optic nerve. Optic atrophy may also be referred to as optic nerve head pallor because of the pale appearance of the optic nerve head as seen at the back of the eye. Possible causes of optic atrophy include: optic neuritis, Leber's...

A form of antisocial behavior disorder characterized by opposition to authority figures such as parents and teachers, and by excessive anger and hostility. Depending on the population, 2-6% of children have oppositional-defiant disorder.Oppositional-defiant disorder is similar to conduct disorder , without the more severe behavior components of aggression ,...

Definition Ophthalmoplegia is a paralysis or weakness of one or more of the muscles that control eye movement. The condition can be caused by any of several neurologic disorders. It may be myopathic, meaning that the muscles controlling eye movement are directly involved, or neurogenic, meaning that the nerve pathways controlling eye muscles are affected. Diseases associated with ophthalmoplegia are...

Definition Oophorectomy is the surgical removal of one or both ovaries. It is also called ovariectomy or ovarian ablation. If one ovary is removed, a woman may continue to menstruate and have children. If both ovaries are removed, menstruation stops and a woman loses the ability to have children. Purpose Oophorectomy is performed to: ·         remove cancerous...

Definition Onychomycosis is a fungal infection of the fingernails or toenails. The actual infection is of the bed of the nail and of the plate under the surface of the nail. Description Onychomycosis is the most common of all diseases of the nails in adults. In North America, the incidence falls roughly between 2-13%. The incidence of onychomycosis is also greater in older adults, and up...

Definition Essential to human health, omega-3 fatty acids are a form of polyunsaturated fats that are not made by the body and must be obtained from a person's food. Purpose Eating foods rich in omega-3 fatty acids is part of a healthy diet and helps people maintain their health. Description In recent years, a great deal of attention has been placed on the value of...

Definition Medical dictionaries define oligomenorrhea as infrequent or very light menstruation. But physicians typically apply a narrower definition, restricting the diagnosis of oligomenorrhea to women whose periods were regularly established before they developed problems with infrequent flow. With oligomenorrhea, menstrual periods occur at intervals of greater than 35 days, with only four...

Definition Occupational asthma is a form of lung disease in which the breathing passages shrink, swell, or become inflamed or congested as a result of exposure to irritants in the workplace.   Description As many as 15% of all cases of asthma may be related to on-the-job exposure to: ·        ...

Definition Obstetrical emergencies are life-threatening medical conditions that occur in pregnancy or during or after labor and delivery. Description There are a number of illnesses and disorders of pregnancy that can threaten the well-being of both mother and child. Obstetrical emergencies may also occur during active labor, and after delivery (postpartum). Obstetrical emergencies of...

Definition Obsessive-compulsive disorder (OCD) is a type of anxiety disorder. Anxiety disorder is the experience of prolonged, excessive worry about circumstances in one's life. OCD is characterized by distressing repetitive thoughts, impulses or images that are intense, frightening, absurd, or unusual. These thoughts are followed by ritualized...

Definition Obesity surgery is an operation that reduces or bypasses the stomach or small intestine so that severely overweight people can achieve significant and permanent weight loss. Purpose Obesity surgery, also called bariatric surgery, is performed only on severely overweight people who are more than twice their ideal weight. This level of obesity often is referred...

Definition Obesity is the condition of having an excessive accumulation of fat in the body, resulting in a body weight more than 20% above the average for height, age, sex, and body type, and in elevated risk of disability, illness, and death. Description The human body is composed of bone, muscle, specialized organ tissues, and fat. Together, all of these tissues comprise the total body mass, which is...

Definition Ovarian cancer is a disease in which the cells in the ovaries become abnormal, start to grow uncontrollably, and form tumors. Ninety percent of all ovarian cancers develop in the cells that line the surface of the ovaries and are called epithelial cell tumors. Description The ovaries are a pair of almond-shaped organs that lie in the pelvis on either side of the uterus. The fallopian tubes connect...

This condition is caused by one or both of two factors: overeating and lack of exercise. There may be other contributing factors, mostly psychological. Overweight is a great handicap to general health and life expectancy. Overweight and Obesity

(See Sweating.) A. Odors From the Skin. Odors from a person's skin or clothing may result from lack of cleanliness or from some skin disease. Sweat-fluid from the sweat glands-is normally odorless. Glands in the skin produce a certain amount of oil. These two products (sweat and oil), particularly when produced in excess, undergo chemical changes as a result of bacterial action; and this decomposed mixture...

Definition of Ovarian cysts: An ovarian cyst is a sac filled with fluid that forms on or inside of an ovary. Causes, incidence, and risk factors: Ovarian cysts may occur during the process in which an egg is released from the ovary (ovulation). During the days before ovulation, a follicle grows. But when ovulation is supposed to occur, the follicle fails to break open and release an egg, as it is supposed...