ich

(ick), The most common disease of aquarium fish; Ichthyophthirius multifilis is a large ciliated protozoan; has a 2-week life cycle. Tomites (liberated by cysts) are susceptible to treatment with malachite green and formaldehyde in combination; tomites embed into fins and scales where they produce many small superficial white papules that lodge the adult phase of the pathogen. Synonym(s): white spot disease (2)

ich

(ĭk)n. A contagious disease of freshwater fishes, caused by a ciliated protozoan (Ichthyophthirius multifiliis) and characterized by small white pustules on the skin and eyes.

ICH

Abbreviation for International Conference on Harmonization; intracranial hypertension.

hemorrhage

(hem'(o-)raj) [ hem- + -rrhage] Blood loss. The term is usually used for episodes of bleeding that last more than a few minutes, compromise organ or tissue perfusion, or threaten life. The most hazardous forms of blood loss result from arterial bleeding, internal bleeding, or bleeding into the cranium. The risk of uncontrolled bleeding is greatest in patients who have coagulation disorders or take anticoagulant drugs.hemorrhagic (hem-o-raj'ik), adjective See: table

Symptoms

Orthostatic dizziness, weakness, fatigue, shortness of breath, and palpitations are common symptoms of hemorrhage. Signs of hemorrhage include tachycardia, hypotension, pallor, and cold moist skin.

Treatment

Pressure should be applied directly to any obviously bleeding body part, and the part should be elevated. Cautery may be used to stop bleeding from visible vessels. Ligation of blood vessels, surgical removal of hemorrhaging organs, or the instillation of sclerosants is often effective in managing internal hemorrhage. Procoagulants (such as vitamin K, fresh frozen plasma, cryoprecipitate, desmopressin) may be administered to patients with primary or drug-induced bleeding disorders. Transfusions of red blood cells may be given if bleeding compromises heart or lung function or threatens to do so because of its pace or volume.

For trauma patients with massive bleeding, the experienced nurse or emergency care provider may apply pneumatic splints or antishock garments during patient transportation to the hospital. These devices may prevent hemorrhagic shock.

CAUTION!

Standard precautions should be used for all procedures involving contact with blood or wounds.

antepartum hemorrhage

Excessive blood loss during the prenatal period, most commonly associated with spontaneous or induced abortion, ruptured ectopic pregnancy, placenta previa, or abruptio placentae.

arterial hemorrhage

A hemorrhage from an artery. In arterial bleeding, which is bright red, the blood ordinarily flows in waves or spurts; however, the flow may be steady if the torn artery is deep or buried.

First Aid

Almost all arterial bleeding can be controlled with direct pressure to the wound. If it cannot be controlled with applied pressure, the responsible artery may need to be surgically ligated. See: arterial bleeding for table; pressure point

capillary hemorrhage

Bleeding from minute blood vessels, present in all bleeding. When large vessels are not injured, capillary bleeding may be controlled by simple elevation and pressure with a sterile dry compress.

carotid artery hemorrhage

Bleeding from the carotid artery. This type of hemorrhage can be rapidly fatal because it may be profuse and may deprive the brain of oxygen.

First Aid

The wound should be compressed with the thumbs placed transversely across the neck, both above and below the wound, and the fingers directed around the back of the neck to aid in compression. Urgent surgical consultation is required.

cerebral hemorrhage

Bleeding into the brain, a common cause of stroke. See: stroke

Etiology

It usually results from rupture of aneurysm, extremely high blood pressure, brain trauma, or brain tumors.

Symptoms

Most people with intracerebral bleeding experience headache. This type of hemorrhage may cause symptoms of stroke (such as unconsciousness, apnea, vomiting, hemiplegia) and death. There may be speech disturbance, incontinence of the bladder and rectum, or other findings, depending on the area of brain damage.

Treatment

Supportive therapy is needed to maintain airway and oxygenation. Neurosurgical consultation should be promptly obtained. Hydration and fluid and electrolyte balance should be maintained. Rehabilitation may include physical therapy, speech therapy, and counseling.

choroidal hemorrhage

Bleeding into the choroid of the eye, a complication of systemic anticoagulation, hypertension, macular degeneration, some ocular surgeries, and ocular metastases of malignant tumors. Visual impairment resulting from the bleeding is usually significant.

eight-ball hemorrhage

A hyphema in which the anterior chamber of the eye fills completely with blood.

fetomaternal hemorrhage

Abbreviation: FMH
The transfer of fetal blood cells through the placenta into the maternal circulation, usually at the time of delivery. Less than 1 ml is considered normal, but greater than 30 ml, as in trauma or placental abruption, is a major cause of fetal morbidity and death. The condition often occurs during pregnancy and may result in the immunization of the mother against Rh antigens in the fetus, esp. when the mother is Rh-negative and the child is Rh-positive. See: Kleihauer-Betke test

fibrinolytic hemorrhage

A hemorrhage due to a defect in the fibrin component in blood coagulation.

gastrointestinal hemorrhage

Gastrointestinal bleeding.

internal hemorrhage

Occult bleeding.

intracranial hemorrhage

Abbreviation: ICH
Bleeding into the cranium. It is a devastating form of stroke with a high rate of mortality.

Patient care

Patients with ICH should be treated emergently with infusions of recombinant factor VIIa in an intensive care unit, where minute-to-minute monitoring of intracranial pressures, blood glucose levels, neurological status, and hemodynamics can be carried out. Patients should initially be kept at bedrest with the head of the bed elevated. Fever should be suppressed and seizures prevented with the administration of anticonvulsant drugs. As the patient stabilizes, rehabilitation supervised by occupational therapists, physical therapists, and speech therapists should be initiated.

hemorrhage of the knee

Bleeding from the knee.

Treatment

If the bleeding is at the knee or below, a pad should be applied with pressure. If the bleeding is behind the knee, a pad should be applied at the site and the leg bandaged firmly. The bandage should be loosened at 12-min to 15-min intervals to prevent arterial obstruction.

lung hemorrhage

Hemorrhage from the lung, with bright red and frothy blood, frequently coughed up.

nasal hemorrhage

Epistaxis.

petechial hemorrhage

Hemorrhage in the form of small rounded spots or petechiae occurring in the skin or mucous membranes.

postmenopausal hemorrhage

Bleeding from the uterus after menopause.

postpartum hemorrhage

Abbreviation: PPH
Hemorrhage that occurs after childbirth. It is a major cause of maternal morbidity and mortality in childbirth. Early postpartum hemorrhage is defined as a blood loss of more than 500 ml of blood during the first 24 hr after delivery. The most common cause is loss of uterine tone caused by overdistention. Other causes include prolonged or precipitate labor; uterine overstimulation; trauma, rupture, or inversion; lacerations of the lower genital tract; or blood coagulation disorders. Late postpartum hemorrhage occurs after the first 24 hr have passed. It usually is caused by retained placental fragments.

Patient care

Many instances of PPH can be prevented with the administration of oxytocin, misoprostol, or other uterotonic medications. The woman's prenatal, labor, and delivery records are reviewed. The presence of risk factors is noted, and the woman's pulse, blood pressure, fundal and bladder status, and vaginal discharge are assessed every 15 min. If the fundus is boggy, it is massaged to stimulate uterine contractions, and then the status of the woman's bladder is assessed. If the bladder is distended, the patient is encouraged to void and then postvoiding fundal status is assessed; if the fundus remains firm after massage, the fundus and vaginal flow are reassessed in 5 min. See: fundal massage

If bleeding does not respond to the above measures or if the fundus remains firm and the patient exhibits bright red vaginal discharge, retained placental fragments or cervical or vaginal laceration should be suspected; the practitioner who delivered the baby should be notified. Continued massage at this point is contraindicated; the physician or nurse midwife may order uterotonic agents to stimulate uterine contractions. Vital signs should be closely monitored. Common findings in hemorrhage include an increase in pulse rate, often associated with a drop in blood pressure. Pharmacological agents such as methylergonovine or prostaglandin F2 analogs may be administered intramuscularly or intravenously. If blood loss has been extensive, intravenous infusions or blood transfusion may be needed to combat hypovolemic shock. If the patient exhibits signs of a clotting defect, prompt life-saving treatment is imperative. See: disseminated intravascular coagulation

The patient is prepared for and the primary caregiver is assisted with examination of the uterine cavity, removal of any placental fragments, or repair of any lacerations. To reduce the patient's anxiety, all procedures are explained, support and comfort are provided, and the mother is assured that her newborn is receiving good care.

primary hemorrhage

A hemorrhage immediately following any trauma.

retroperitoneal hemorrhage

Bleeding into the retroperitoneal space.

secondary hemorrhage

1. A hemorrhage occurring some time after primary hemorrhage, usually caused by sepsis and septic ulceration into a blood vessel. It may occur after 24 hr or when a ligature separates, usually between the 7th and 10th days. 2. Bleeding from the mother's uterus or the infant's umbilicus, resulting from a septic infection.

splinter hemorrhage

A small linear hemorrhage under the fingernails or toenails. It may be due to subacute bacterial endocarditis.

subarachnoid hemorrhage

Abbreviation: SAH
Bleeding into the subarachnoid space of the brain, usually because of the rupture of an intracranial aneurysm or arteriovenous malformation, and occasionally because of hypertensive vascular disease. The bleeding causes intense headache pain, often with nausea and vomiting, loss of consciousness, paralysis, and, in some cases, coma, decerebrate posturing, and brain death. About 30,000 Americans are affected annually. Prompt diagnosis is facilitated by neuroimaging or lumbar puncture. A neurosurgical consultation should be obtained.

SUBCONJUNCTIVAL HEMORRHAGE

subconjunctival hemorrhage

Rupture of the superficial capillaries with associated hemorrhage into the subconjunctival space.

Etiology

Subconjunctival hemorrhage can result from blunt trauma to the eye or from increased intracranial or intraocular pressure.

Symptoms

Patients have visible bleeding between the sclera and the conjunctiva.

Treatment

A subconjunctival hemorrhage normally resolves within 1 to 7 days.

illustration

thigh hemorrhage

Bleeding at the upper part of the thigh, near the groin.

Treatment

A pad or gauze should be inserted into the wound and pressure applied. Failure of the bleeding to stop requires surgical consultation.

typhoid hemorrhage

Gastrointestinal (GI) bleeding due to ulceration of the upper GI tract, typically during the second or third week of untreated typhoid.

uterine hemorrhage

Hemorrhage into the cavity of the uterus. The three types of pathologic uterine hemorrhage are essential uterine hemorrhage (metropathia haemorrhagica), which occurs with pelvic, uterine, or cervical diseases; intrapartum hemorrhage, which occurs during labor; and postpartum hemorrhage, which occurs after the third stage of labor. The last may be caused by rupture, lacerations, relaxation of the uterus, hematoma, or retained products of conception, including the placenta or membrane fragments.

Etiology

Common causes are trauma; congenital abnormalities; pathologic processes (such as tumors; infections, esp. of the alimentary, respiratory, and genitourinary tracts); and generalized vascular disorders such as purpuras and coagulation defects. Hemorrhage may also result from premature separation of the placenta, particularly with extravasation into the uterine musculature, and from retained products of conception after abortion or delivery. See: abruptio placentae; Couvelaire uterus

Treatment

An umbrella pack will apply pressure to the uterine arterial supply. When ultrasonography reveals that retained placental fragments are the source of hemorrhage, they are usually removed by suction or surgical curettage. If the uterus is flaccid, it can usually be stimulated to contract by administering intravenous oxytocin. The patient may need transfusion and, in some cases, surgery to prevent fatal hemorrhage.

variceal hemorrhage

See: esophageal varix

venous hemorrhage

Hemorrhage from a vein, characterized by steady, profuse bleeding of rather dark blood.

Patient care

The patient should be reassured while direct pressure to the wound is applied and the affected body part is elevated. If bleeding does not stop after 15 min of direct pressure, evaluation by a health care provider is advisable. Vital signs should be monitored whenever bleeding does not stop with direct pressure, and IV fluids should be initiated as necessary to prevent hypovolemic shock.

vicarious hemorrhage

Hemorrhage from one part as a result of suppression of bleeding in another part. See: vicarious menstruation.

Location	Descriptive Term
Biliary tract	Hemobilia
Fallopian tubes	Hemosalpinx
Lower GI tract	Hematochezia; melena
Upper GI tract	Hematemesis
Joints	Hemarthosis
Lungs/Bronchi (coughed up)	Hemoptysis
Nasal passages	Epistaxis
Skin	Ecchymosis
Urinary tract	Hematuria

intracranial hemorrhage

Abbreviation: ICH
Bleeding into the cranium. It is a devastating form of stroke with a high rate of mortality.

Patient care

hypertension

(hi?per-ten'shon ) [ hyper- + tension],

HTN

In adults, a condition in which the blood pressure (BP) is higher than 140 mm Hg systolic or 90 mm Hg diastolic on three separate readings recorded several weeks apart. Hypertension is one of the major risk factors for coronary artery disease, heart failure, stroke, peripheral vascular disease, kidney failure, and retinopathy. It affects about 50 million people in the U.S. Considerable research has shown that controlling HTN increases longevity and helps prevent cardiovascular illnesses. Synonym: high blood pressure See: blood pressurehypertensive (hi?per-ten'siv), adjective

All systems for categorizing high BP are somewhat arbitrary, but the current consensus is that normal BPs are < 120 mm Hg systolic and < 80 mm Hg diastolic. Borderline high BPs (prehypertension) are between 120 and 139 mm Hg systolic and 80 to 89 mm Hg diastolic. Patients with BP readings between 140/90 and 160/100 mm Hg are said to have stage 1 HTN.

Stage 2 HTN is a pressure from 160/100 to 179/109 mm Hg. Stage 3 HTN begins at 180/110 mm Hg and has no upper limit. At each stage of HTN, from prehypertensive levels through the three stages of HTN, the risks of strokes, heart attacks, and kidney failure increase. See: table

Hypertension in children has been defined as BP above the 95th percentile for age, height, and weight. As many as 28% of children have secondary HTN compared to 1% to 5% in adults.

Etiology

Hypertension results from many different conditions, some curable and others treatable. Curable forms of HTN (secondary HTN), which are relatively rare, may be caused by coarctation of the aorta, pheochromocytoma, renal artery stenosis, primary aldosteronism, and Cushing's syndrome. Excess alcohol consumption (more than two drinks daily) is a common cause of high BP; abstinence or drinking in moderation effectively lowers BP in these cases. Aortic valve stenosis, pregnancy, obesity, and the use of certain drugs (such as cocaine, amphetamines, steroids, or erythropoietin) also may lead to hypertension. Usually, however, the cause is unknown; then high BP is categorized as primary, essential, or idiopathic. Primary hypertension may result from the body's resistance to the action of insulin, hyperactivity of the sympathetic nervous system, hyperactivity of the renin-angiotensin-aldosterone system, or endothelial dysfunction.

Symptoms

Hypertension is usually a silent (asymptomatic) disease in the first few decades of its course. Because most patients are symptom-free until complications arise, they may have difficulty taking seriously a condition from which they perceive no immediate danger. Occasionally, patients with HTN report headache. When complications result from high BPs, patients mention symptoms referable to the affected organs.

Treatment

If HTN is newly diagnosed, routine studies should be done on the patient to establish a baseline for treatment. In addition to a thorough patient history, assessment for risk factors, and physical examination, these studies include an ECG, urinalysis, serum potassium and calcium levels, blood urea nitrogen, fasting glucose level, and cholesterol profile, including triglycerides. The Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC) guidelines to reduce cardiovascular disease complications recommends a target blood pressure of less than 140/90; 130/80 for patients with diabetes mellitus or renal disease. Because HTN has been identified as a growing concern among children, the JNC recommends regular BP checks beginning at age 3. Lifestyle modifications that lower BP include dietary sodium restriction to about 2 g/day, made possible by avoiding salted food such as ham, potato chips, and processed foods and by not adding salt to food at the table; maintaining a healthy weight (a body mass index above 24.9 can elevate BP); eating lower-calorie foods; restricting total cholesterol and saturated fat intake; quitting smoking; limiting alcohol intake (to about one drink daily); and participating in a program of regular exercise. When lifestyle modifications fail over the course of several months to control BP naturally, medications should be used. Drug therapy for stage 1 HTN includes low-dose thiazide diuretics for most patients, although angiotensin converting enzyme (ACE) inhibitors, beta blockers, calcium channel blockers or a combination of these may be prescribed. For stage 2 HTN, two-drug combinations are prescribed for most patients, usually a thiazide-type diuretic along with a beta blocker, ACE inhibitors, angiotensin receptor blockers, alpha blockers, or centrally active alpha blocking agents. If a woman develops HTN during pregnancy, treatment should be with methyldopa, a beta blocker, or a vasodilator, as these drugs provide the least risk to the fetus. See: table pregnancy-induced hypertension

Patient care

Blood pressure should be checked at every health care visit, and patients should be informed of their BP reading and its meaning. Positive lifestyle changes should be encouraged. Adherence to medical regimens is also emphasized, and patients are advised to inform their health care providers of any side effects of therapy that they experience because these can often be managed with dosage adjustment or a change in medication. The technique of home BP monitoring is taught to receptive patients. Pressures should be measured and recorded for both arms, unless there is a medical prohibition for one arm, indicating which arm was used for each reading.

accelerated hypertension

A significant increase in BP, with some evidence of vascular damage on funduscopic examination of the retina. Prompt treatment is indicated to prevent organ damage. See: malignant hypertension

benign intracranial hypertension

Pseudotumor cerebri.

chronic thromboembolic pulmonary hypertension

Abbreviation: CTEPH
Pulmonary HTN that results from the migration of blood clots (usually from the lower extremities) into the lungs. Elevated BP in the lungs gradually overloads the right ventricle and causes right-sided heart failure.

Symptoms

Symptoms usually include shortness of breath, esp. during exercise.

Treatment

The disease, when identified, may be treated with surgical removal of blood clots.

cuff-inflation hypertension

A marked increase in BP in association with inflation of the sphygmomanometer cuff. This does not represent true hypertension.

drug-resistant hypertension

Resistant hypertension.

essential hypertension

Hypertension that develops without apparent cause. Synonym: primaryhypertension

gestational hypertension

High BP developing after 20 weeks of pregnancy. It may be mild; it often resolves after delivery, and it usually does not produce proteinuria or other features of preeclampsia.

Goldblatt hypertension

See: Goldblatt, Harry

idiopathic intracranial hypertension

Pseudotumor cerebri.

intra-abdominal hypertension

Abbreviation: IAH
An increase in measured abdominal pressures, from a normal of 0 mm Hg to levels between 15 and 20 mm Hg. It may occur in patients with multiple traumatic injuries to the abdomen or with intraperitoneal diseases, e.g., severe pancreatitis. It is associated with the development of abdominal compartment syndrome, shock, and multiple organ failure.

intracranial hypertension

Abbreviation: ICH
An increase in the pressure inside the skull from any cause such as a tumor, hydrocephalus, intracranial hemorrhage, trauma, infection, or interference with the venous flow from the brain. See: hydrocephalus

CAUTION!

Patients with intracranial HTN should not undergo a lumbar puncture or any other procedure that decreases the cerebrospinal fluid pressure in the vertebral canal.

malignant hypertension

A form of HTN that progresses rapidly, accompanied by severe vascular damage. It may be life-threatening or cause stroke, encephalopathy, cardiac ischemia, or renal failure.

masked hypertension

Elevated BP that is not identified during professional evaluations in the office but only during ambulatory home blood pressure monitoring.

ocular hypertension

Increased intraocular pressure, typically exceeding 21 mm Hg. This condition, present in glaucoma, may predispose affected persons to optic nerve damage and visual field loss.

permissive hypertension

The temporary ignoring of the treatment of elevated blood pressures in patients with acute stroke or transient ischemic attack (TIA).

CAUTION!

In these conditions the rapid lowering of blood pressure to normal ranges (< 140/90 mm Hg) may worsen neurological deficits.

portal hypertension

Hypertension in the portal vein caused by an obstruction of the flow of blood through the liver. It is found in diseases such as cirrhosis, in which it is responsible for ascites, splenomegaly, and the formation of varices.

pregnancy-induced hypertension

Abbreviation: PIH
High blood pressure, proteinuria, and edema occurring during pregnancy. Diagnostic criteria include an increase of 30 mm Hg systolic or 15 mm Hg diastolic over the baseline pressure for the individual woman (or readings of 140/90) on two assessments with at least a 6-hr interval between measures; edema; and proteinuria of at least 300 mg/24 hr. PIH occurs most commonly in the late second trimester or last trimester, but it may manifest earlier in women with molar pregnancies. It is potentially life-threatening and may worsen rapidly and, if untreated, develop into eclampsia. See: eclampsia; HELLP syndrome; preeclampsia

Etiology

The cause of PIH is unknown, but there are several major contributing theories: vasoconstriction and vasospasm, and a possible imbalance between prostaglandins, prostacyclin, and thromboxane A². The incidence is higher among adolescent and older primigravidas, diabetics, and women with pre-exisitng vascular problems or multiple pregnancies. Geographical, ethnic, racial, familial, low socioeconomic, nutritional, and immunological factors may contribute to PIH. Characteristic complaints include sudden weight gain, severe frontal headaches, and visual disturbances. Indications of increasing severity include complaints of epigastric or abdominal pain; generalized, presacral, and facial edema; oliguria; and hyperreflexia.

The treatment consists of bedrest, a high-protein diet, and medications including mild sedatives, antihypertensives, and intravenous anticoagulants if indicated. Complications are HELLP syndrome (hemolysis, elevated liver enzymes and low platelets) and eclampsia (the convulsive form of PIH).

Patient care

To enable the woman to actively participate in her health maintenance, reduce the potential for development of PIH, and facilitate early diagnosis and treatment, the health care provider should emphasize the importance of regular prenatal visits and good prenatal nutrition. Signs to report promptly are identified with the patient: sudden weight gain, swelling of the hands and face, headache, pitting edema of the ankles and legs, and reduced urine output.

At each prenatal visit, the pregnant woman's BP is monitored. The patient also is assessed for albuminuria; weekly weight gain of more than 3 lb (1.36 kg) in the second trimester or more than 1 lb (0.45 kg) in the third trimester; and generalized edema, esp. of the face and hands, and pitting edema of the ankles and legs. Protein intake is monitored to ensure adequate maternal serum protein levels, normal oncotic pressure, limitation of edema formation, and normal fetal development.

As preeclampsia progresses, the woman may complain of headaches, blurred vision or other visual disturbances, epigastric pain or heartburn, chest pressure, irritability, emotional tension, and decreased fetal activity. The patient is assessed for hyperreflexia of the deep tendon reflexes and clonus, and, if preeclampsia worsens, for oliguria. The goals of treatment are to stop progress of the condition and to ensure survival of the fetus and the mother's health.

Hospitalization may be necessary if the patient exhibits signs of moderate to severe preeclampsia and has failed to respond to home management. Intravenous magnesium sulfate may be given, first as a bolus and continued as a maintenance dose, until the severity of the disease decreases. If magnesium sulfate is used, the patient must be assessed frequently for the presence of deep tendon reflexes, respirations over 12 per minute, hourly urine output, and signs and symptoms of magnesium toxicity. Calcium gluconate, if needed, is the antidote for magnesium sulfate.

The clinical status of mother and fetus is continually evaluated; maternal vital signs and fetal heart rate are monitored. The patient is assessed for impending labor, and fetal and maternal responses to labor contractions are evaluated. The obstetrician is notified of any change in the patient's or the fetus' condition. Emergency care is provided during convulsions; prescribed medications are administered as directed, and patient and fetal response are evaluated. Careful monitoring of the administration of magnesium sulfate, intake and output, and the woman's response to the medication are necessary. Health care providers should be esp. alert for signs of toxicity, e.g., an absence of patellar reflexes (hyporeflexia), flushing, and muscle flaccidity.

Psychological support and assistance to develop effective coping strategies are provided to both patient and family, who are to be prepared for possible premature delivery. Cesarean birth or oxytocin induction may be required. Although infants of mothers with PIH are usually small for gestational age, they sometimes fare better than other premature infants of similar weight because they have developed adaptive ventilatory and other responses to intrauterine stress.

primary hypertension

Essential hypertension.

pulmonary hypertension

Hypertension in the pulmonary arteries (above 25 to 30 mm Hg). Primary pulmonary hypertension is a rare familial illness in which small pulmonary arteries become blocked as a result of abnormalities in the structure of blood vessels in the lung. Secondary pulmonary hypertension is an elevation in pulmonary artery pressure as a result of left ventricular failure, blood clots in the pulmonary arteries, or chronic lung diseases.

rebound hypertension

Hypertension after withdrawal of an antihypertensive drug.

renal hypertension

1. Hypertension produced by kidney disease. It is caused by alteration in the renal regulation of sodium and fluids or by alteration in renal secretion of vasoconstrictors, which alter the tone of systemic or local arterioles. 2. Hypertension produced experimentally by constriction of renal arteries. It is due to a humoral substance (renin) produced in an ischemic kidney.

renovascular hypertension

Hypertension that is caused by decreased blood flow through one or both renal arteries and that normalizes after angioplasty or surgery to open the affected artery. It is an uncommon but surgically treatable form of high blood pressure.

resistant hypertension

Hypertension that does not normalize with the use of a diuretic medication plus optimal doses of two additional antihypertensive drugs. Synonym: drug-resistant hypertension.

venous hypertension

Hypertension in the legs of patients with venous insufficiency. Its hallmark is pain in the legs when the patient is standing or sitting and dangling his legs but not when lying down.

white coat hypertension

A colloquial term for an episode of hypertension when the reading is taken by a health care professional. It is attributed to anxiety over medical examination procedures or fear of possible findings. *Not taking antihypertensive drugs and not acutely ill. When systolic and diastolic BPs fall into different categories, the higher category should be selected to classify the person's BP status. For example, 160/92 mm Hg should be classified as stage 2 HTN, and 174/120 mm Hg should be classified as stage 3 HTN. Isolated systolic HTN is defined as systolic BP of 140 mm Hg or greater and diastolic BP below 90 mm Hg and staged appropriately (e.g., 170/82 mm Hg is defined as stage 2 isolated systolic HTN). In addition to classifying stages of HTN on the basis of average BP levels, clinicians should specify presence or absence of target organ disease and additional risk factors. This specificity is important for risk classification and treatment. † Optimal blood pressure with respect to cardiovascular risk is below 120/80 mm Hg. However, unusually low readings should be evaluated for clinical significance. ‡ Based on the average of two or more readings taken after a period of rest and using the correct techniques at each of two or more visits after an initial screening. SOURCE: Adapted from the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High BP, NIH publication No. 98-4080, November 1997, and other sources.

Category	Systolic (mm Hg)		Diastolic (mm Hg)
Optimal†	120	and	80
Prehypertension	120–139	or	80–89
Hypertension‡
Stage 1	140–159	or	90–99
Stage 2	160–179	or	100–109
Stage 3	= 180	or	= 110

Intervention	Approximate Decrease (in mm Hg)
Weight loss (20 pounds)	5 - 10
Dietary approaches to stop hypertension (DASH) diet	8 - 14
Regular exercise	4 - 9
Reducing sodium intake	2 - 8
Limiting alcohol intake to one or two drinks a day	2 - 4

intracranial hypertension

CAUTION!

Patients with intracranial HTN should not undergo a lumbar puncture or any other procedure that decreases the cerebrospinal fluid pressure in the vertebral canal. See also: hypertension

International Conference on Harmonization of Technical Requirements for Registration of Pharmaceutics for Human Use

ICH

A global effort of pharmaceutical regulatory agencies in Asia, Europe, and the United States to standardize and streamline the approval of new drugs for use in human patients.