The following are health and medical definitions of terms that appear in the Alopecia Areata article.
Acquired: Anything that is not present at birth but develops some time later. In medicine, the word "acquired" implies "new" or "added." An acquired condition is "new" in the sense that it is not genetic (inherited) and "added" in the sense that was not present at birth. See the entire definition of Acquired
Alopecia:Baldness. There are many types of alopecia, each with a different cause. Alopecia may be localized to the front and top of the head as in common male pattern baldness. It may be patchy as in a condition called alopecia areata. Or it can involve the entire head as in alopecia capitis totalis. The word "alopecia" comes from the Greek "alopex" for "fox." Foxes are less furry when afflicted with a skin disease (the "mange") which causes them to lose their hair. When a fancier word for "baldness" was sought, the mangy fox supplied it -- "alopecia" or, if you wish, "fox-mange" -- not a very positive image to associate with baldness!
Alopecia areata: A patchy baldness which typically begins with patchy hair loss on the scalp and sometimes progresses to complete baldness and even loss of body hair. The hair loss tends to be rather rapid and asymmetrical and is different than male pattern baldness. See the entire definition of Alopecia areata
Alopecia universalis: Absence of all of the hair, not only on the scalp, but also on the entire body. Affected individuals are born without eyebrows and eyelashes and never develop axillary or pubic hair. There are hair follicles but they are devoid of hair. The disorder is inherited as an autosomal recessive trait. It is caused by a mutation in a gene dubbed HR in chromosome band 8p21.2 that is the human homolog of the mouse "hairless" gene -- the human version of the gene in the mouse that is responsible for hairless mice. See the entire definition of Alopecia universalis
Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself. See the entire definition of Autoimmune
Autoimmunity: A misdirected immune response that occurs when the immune system goes awry and attacks the body itself. See the entire definition of Autoimmunity
Biopsy: The removal of a sample of tissue for purposes of diagnosis. (Many definitions of "biopsy" stipulate that the sample of tissue is removed for examination under a microscope. This may or may not be the case. The diagnosis may be achieved by other means such as by analysis of chromosomes or genes.) See the entire definition of Biopsy
Birth control: Birth control is the use of any practices, methods, or devices to prevent pregnancy from occurring in a sexually active woman. Also referred to as family planning, pregnancy prevention, fertility control, or contraception; birth control methods are designed either to prevent fertilization of an egg or implantation of a fertilized egg in the uterus. See the entire definition of Birth control
Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time. See the entire definition of Chronic
Colitis: Inflammation of the large intestine (the colon). There are many forms of colitis, including ulcerative colitis, Crohn's disease, infectious, pseudomembranous, and spastic. For example, intermittent rectal bleeding, crampy abdominal pain and diarrhea can be symptoms of ulcerative colitis. Diagnosis can be made by barium enema, but direct visualization (sigmoidoscopy or colonoscopy) is the most accurate test. Long-standing ulcerative colitis increases the risk for colon cancer. Ulcerative colitis can also be associated with inflammation in joints, spine, skin, eyes, the liver and its bile ducts. Treatment of ulcerative colitis can involve medications and surgery.
Diagnosis:1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV. See the entire definition of Diagnosis
Estrogen: Estrogen is a female hormone produced by the ovaries. Estrogen deficiency can lead to osteoporosis. See the entire definition of Estrogen
Genes: The basic biological units of heredity. Segments of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Genes
Hair loss: Hair loss is the thinning of hair on the scalp. The medical term for hair loss is alopecia. Alopecia can be temporary or permanent. The most common form of hair loss occurs gradually and is referred to as "androgenetic alopecia," meaning that a combination of hormones (androgens are male hormones) and heredity (genetics) is needed to develop the condition. Other types of hair loss include alopecia areata (patches of baldness that usually grow back), telogen effluvium (rapid shedding after childbirth, fever, or sudden weight loss); and traction alopecia (thinning from tight braids or ponytails). See the entire definition of Hair loss
Immune: Protected against infection. The Latin immunis means free, exempt.
Immune system: A complex system that is responsible for distinguishing us from everything foreign to us, and for protecting us against infections and foreign substances. The immune system works to seek and kill invaders. See the entire definition of Immune system
Lupus: A chronic inflammatory condition caused by an autoimmune disease. An autoimmune disease occurs when the body's tissues are attacked by its own immune system. Patients with lupus have unusual antibodies in their blood that are targeted against their own body tissues. See the entire definition of Lupus
Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis. There is always an onset to a disease but never to the return to good health. The default setting is good health. See the entire definition of Onset
Orifice: An opening. The mouth for example is an orifice.
Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long. See the entire definition of Pregnancy
Progesterone: A female hormone and the principal progestational hormone that is made mainly by the corpus luteum in the ovary and by the placenta. Progesterone prepares the lining (endometrium) of the uterus (the womb) to receive and sustain the fertilized egg and so permits pregnancy. Similarly refers to synthetic versions of the hormone. Also known as progestational hormone.
Remission: Disappearance of the signs and symptoms of cancer or other disease. When this happens, the disease is said to be "in remission." A remission can be temporary or permanent.
Rheumatoid arthritis: An autoimmune disease which causes chronic inflammation of the joints, the tissue around the joints, as well as other organs in the body. Autoimmune diseases occur when the body tissues are mistakenly attacked by its own immune system. The immune system is a complex organization of cells and antibodies designed normally to "seek and destroy" invaders of the body, particularly infections. Patients with these diseases have antibodies in their blood which target their own body tissues, where they can be associated with inflammation. Because it can affect multiple other organs of the body, rheumatoid arthritis is referred to as a systemic illness and is sometimes called rheumatoid disease. While rheumatoid arthritis is a chronic illness (meaning it can last for years) patients may experience long periods without symptoms. See the entire definition of Rheumatoid arthritis
Steroid: A general class of chemical substances that are structurally related to one another and share the same chemical skeleton (a tetracyclic cyclopenta[a]phenanthrene skeleton). See the entire definition of Steroid
Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems. See the entire definition of Stress
Thyroid:1. The thyroid gland. Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism. 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.) See the entire definition of Thyroid
Ulcerative colitis: A relatively common disease that causes inflammation of the large intestine (the colon). The cause is unknown. See the entire definition of Ulcerative colitis
Vitiligo: Pronounced vit-uh-LIE- go. A condition in which the skin turns white due to the loss of melanocytes. These cells produce melanin, the pigment that gives the skin its characteristic color. (Melanocytes also impart color to the retina of the eye and the mucous membrane tissues lining the inside of the mouth, nose, genital and rectal areas). In vitiligo, the melanocytes are mysteriously destroyed, leaving de-pigmented patches of skin on different parts of the body. The hair that grows in areas affected by vitiligo may also turn white. See the entire definition of Vitiligo
There are many causes of scalp hair loss. This featured article covers the common ones such as patchy hair loss (alopecia areata, trichotillomania, and tinea capitis), telogen effluvium, and androgenetic alopecia (male-pattern baldness, female-pattern baldness).
Vitiligo is a condition in which the skin turns white due to the loss of pigment from the melanocytes, cells that produce the pigment melanin that gives the skin color.
Leprosy (Hansen's disease) is a disfiguring disease caused by infection with Mycobacterium leprae bacteria. The disease is spread from person to person through nasal secretions or droplets. Symptoms and signs of leprosy include numbness, loss of temperature sensation, painless ulcers, eye damage, loss of digits, and facial disfigurement. Leprosy is treated with antibiotics and the dosage and length of time of administration depends upon which form of leprosy the patient has.
Leprosy is a disease caused by the bacteria Mycobacterium leprae, which causes
damage to the skin and the peripheral nervous system. The disease develops
slowly (from six months to 40 years!) and results in skin lesions and deformities,
most often affecting the cooler places on the body (for example, eyes, nose,
earlobes, hands, feet, and testicles). The skin lesions and deformities can be
very disfiguring and are the reason that infected individuals historically were considered
outcasts in many cultures. Although human-to-human transmission is the primary
source of infection, three other species can carry and (rarely) transfer M.
leprae to humans: chimpanzees, mangabey monkeys, and nine-banded armadillos. The
disease is termed a chronic granulomatous disease, similar to tuberculosis, because it produces
inflammatory nodules (granulomas) in the skin and nerves over time.