Kids Research Express

Phobia, intense and persistent fear of a specific object, situation, or activity. Because of this intense and persistent fear, the phobic person often leads a constricted life. The anxiety is typically out of proportion to the real situation, and the victim is fully aware that the fear is irrational. Behavioral techniques have proved successful in treating phobias, especially simple and social phobias. One technique, systematic desensitization, involves gradually confronting the phobic person with situations or objects that are increasingly close to the feared ones. Exposure therapy, another behavioral method, has recently been shown more effective. In this technique, phobics are repeatedly exposed to the feared situation or object so that they can see that no harm befalls them; the fear gradually fades. Antianxiety drugs have also been used as palliatives. Antidepressant drugs have also proved successful in treating some phobias.

Phenytoin or Dilantin, drug used to treat the seizures, or violent muscle contractions, caused by epilepsy. The drug can also control seizures associated with surgery of the brain or spinal cord. Phenytoin influences the movement of sodium along nerve fibers, preventing or minimizing the abnormal electrical impulses that cause seizures. Phenytoin is available by prescription in tablet, capsule, and liquid form. Taken orally, except for one liquid form made for injection, the drug is usually prescribed in 100-mg doses taken once a day. The maximum recommended daily dosage is 600 mg. To avoid stomach irritation, oral phenytoin should be taken with food. The drug’s effectiveness is usually apparent after two to three weeks of treatment. Patients with impaired liver function, diabetes, or heart disease should use this drug with caution. Although long-term use of phenytoin is common, it may be associated with the development of cancers in the lymphatic system or the bone marrow (leukemia). ...

Pelvic Inflammatory Disease (PID), bacterial infection of the upper female genital tract, including the uterus , fallopian tubes , and ovaries . PID can be caused by several different aerobic (oxygen-requiring) and anaerobic (non-oxygen-requiring) bacteria. The two most important such bacteria are Neisseria gonorrhoeae, the bacterium that causes gonorrhea, and Chlamydia trachomatis, the bacterium that causes chlamydia. These bacteria are usually transmitted through sexual intercourse with an infected partner. The usual symptoms of acute PID are fever, chills, lower abdominal and pelvic pain, and vaginal discharge or bleeding. These symptoms often begin a few days after the start of a menstrual period, particularly when Neisseria gonorrhoeae is the cause of infection. Infections due to Chlamydia trachomatis usually progress more slowly than those caused by Neisseria gonorrhoeae. On physical examination by a doctor, the uterus, ovaries, and fallopian tubes of the infected person are usu...

Paralysis, loss of voluntary movement in a part of the human body, caused by disease or injury anywhere along the motor-nerve path from the brain to the muscle fiber. Paralysis may result from injury, poisoning, infection, hemorrhage, occluded blood vessels, or tumors. Occasionally paralysis is due to congenital deficiency in motor-nerve development. Permanent paralysis results from extensive damage to nerve cells or to a nerve trunk; severely damaged nerve cells cannot regenerate. Transient or incomplete paralysis, called paresis, is often caused by infections, trauma, or poisons that temporarily suppress motor activity but do not extensively damage nerve cells. Because most of the motor nerves from either half of the brain supply the opposite side of the body, lesions in one part of the brain usually produce paralyses in the opposite half of the body. Paralysis of one limb is known as monoplegia; paralysis of two limbs on the same side of the body as hemiplegia; paralysis of both l...

Panic Disorder, mental illness in which a person experiences repeated, unexpected panic attacks and persistent anxiety about the possibility that the panic attacks will recur. A panic attack is a period of intense fear, apprehension, or discomfort. In panic disorder, the attacks usually occur without warning. Symptoms include a racing heart, shortness of breath, trembling, choking or smothering sensations, and fears of “going crazy,” losing control, or dying from a heart attack. Panic attacks may last from a few seconds to several hours. Most peak within 10 minutes and end within 20 or 30 minutes.

Pain, unpleasant sensory and emotional experience caused by real or potential injury or damage to the body or described in terms of such damage. Scientists believe that pain evolved in the animal kingdom as a valuable three-part warning system. First, it warns of injury. Second, pain protects against further injury by causing a reflexive withdrawal from the source of injury. Finally, pain leads to a period of reduced activity, enabling injuries to heal more efficiently. Pain is difficult to measure in humans because it has an emotional, or psychological component as well as a physical component. Some people express extreme discomfort from relatively small injuries, while others show little or no pain even after suffering severe injury. Sometimes pain is present even though no injury is apparent at all, or pain lingers long after an injury appears to have healed.

Osteoporosis, bone condition characterized by a decrease in mass, resulting in bones that are more porous and more easily fractured than normal bones. Fractures of the wrist, spine, and hip are most common; however, all bones can be affected. White females are the most susceptible, but other risk factors include low calcium intake; inadequate physical activity; certain drugs, such as corticosteroids, and a family history of the disease. The most common form of the disease, primary osteoporosis, includes postmenopausal (see Menopause ), or estrogen-deficient, osteoporosis (Type I), which is observed in women whose ovaries have ceased to produce the hormone estrogen; age-related osteoporosis (Type II), which affects those over the age of 70; and idiopathic osteoporosis, a rare disorder of unknown cause that affects premenopausal women and men who are middle-aged or younger. Secondary osteoporosis may be caused by bone disuse as a result of paralysis or other conditions, including weight...