Blood pressure is determined by the amount of blood pumped by the heart, and the size and condition of the arteries. Many other factors can affect blood pressure, including volume of water in the body; salt content of the body; condition of the kidneys, nervous system, or blood vessels; and levels of various hormones in the body.

"Essential" hypertension has no identifiable cause. It may have genetic factors and environmental factors, such as salt intake or others. Essential hypertension comprises over 95% of all hypertension.

"Secondary" hypertension is hypertension caused by another disorder. This may include:

Follow the health care provider's recommendations to modify, treat, or control possible causes of secondary hypertension.

Symptoms :

Note: Often no symptoms are present.

Additional symptoms that may be associated with this disease:

Hypertension may be suspected when the blood pressure is high. It is confirmed through blood pressure measurements that are repeated over time. Blood pressure consistently elevated over 140 systolic (which indicates the pressure generated when the heart beats) or 90 diastolic (which indicates the pressure when the heart is at rest). The person may show signs of complications.

Tests for suspected causes and complications may be performed. These are guided by the symptoms presented, history, and results of examination.

This disease may also alter the results of the following tests:

ASTHMA

Asthma is a chronic lung disorder of enormous public health importance that affects 8 to 12% of the population and disproportionately affects children, minorities, and persons of lower socioeconomic status.

It is the most frequent cause of pediatric emergency room use and hospital admission and is the leading cause of school absences. The economic costs of asthma are estimated at more than $6 billion/year.
Despite improvements in diagnosis and management, and an increased understanding of the epidemiology, immunology, and biology of the disease, asthma prevalence, morbidity, and mortality have progressively increased over the past 15 years.

In response to the increased prevalence of asthma, NIEHS has developed several research programs.

Primary Prevention:

The EIPPAC Study Secondary Prevention
The Inner-City Asthma Study Risk Assessment
The National Allergen Survey Pathogenesis & Mechanisms
The Pulmonary Pathobiology Program Asthma Genetics
The Environmental Genome Project Centers for Children's Environmental Health
and Disease Prevention Research Community-Based Participatory Research

Cataract

A cloudy or opaque area in the lens of the eye (see also congenital cataracts).

Alternative names
Lens opacity
Causes, incidence, and risk factors

The lens of an eye is normally clear. If the lens becomes cloudy or is opacified it is called a cataract. Cataracts may rarely be present at or shortly after birth in which case they are called congenital cataracts. Adult cataracts usually develop with advancing age and may run in families. Cataracts are accelerated by environmental factors, such as smoking or other toxic substances. Cataracts may develop at any time throughout life following an eye injury. Cataracts may also develop in response to metabolic diseases such as diabetes. Certain medications, such as cortisone, may accelerate cataract formation.

Congenital cataracts are cataracts which are present from birth (or appear shortly after). They may be familial (autosomal dominant inheritance), or they may be caused by congenital infections such as rubella, or associated with metabolic disorders such as galactosemia. Risk factors include inherited metabolic diseases, a family history of cataract, and maternal viral infection.

Adult cataract is generally associated with aging. It develops slowly and painlessly with a gradual  onset of difficulty with vision. Visual problems may include difficulty seeing at night, halos around lights or glare sensitivity, and finally, decreased visual acuity, even in daylight.

Adult cataracts are classified as immature, mature, and hypermature. A lens that has some remaining clear areas is referred to as an immature cataract. A mature cataract is completely opaque. A hypermature cataract has a liquefied surface that leaks through the capsule and may cause inflammation of other structures in the eye.

Most people develop some clouding of the lens after the age of 60. The incidence of visually significant cataract ranges from 50 percent of Americans ages 65 to 74 to about 70 percent of those age 75. Most people with cataract have similar changes in both eyes, although one eye may be worse than the other. Many people with cataract have only minimal visual changes and are not aware of their cataracts. Factors that may contribute to cataract development are low serum calcium levels, diabetes, long-term use of corticosteroids, and various inflammatory and metabolic disorders. Environmental causes include trauma, radiation exposure, and excessive exposure to ultraviolet light (sunlight). In many cases, the cause of cataract is unknown.

Prevention :
The primary prevention involves controlling associated diseases and avoiding exposure to factors known to promote cataract formation.

Wearing sunglasses when you are outside during the day can reduce the amount of UV light your eyes are exposed to. Some sunglasses do not filter out the harmful UV. An optician should be able to tell you which sunglasses filter out the most UV. For patients who smoke cigarettes, quitting will decrease the risk of cataracts.

Symptoms

What Is Cholesterol?

Cholesterol is a waxy, fat-like substance that is made in the body by the liver. Cholesterol forms part of every cell in the body and serves many vital functions. Our bodies need cholesterol to:

Sometimes, however, our bodies make more cholesterol than we really need, and this excess cholesterol circulates in the bloodstream. High levels of cholesterol in the blood can clog blood vessels and increase the risk for heart disease and stroke.

Our bodies can make too much cholesterol when we eat too much saturated fat - the kind of fat found in animal-based foods such as meat and dairy products.

In addition to making cholesterol, we also get a small percentage of our body's cholesterol from the foods we eat. Only animal-based foods such as meat, eggs, and dairy products contain cholesterol. Plant foods such as fruits, vegetables, and grains do not contain cholesterol.

The Different Types Of Cholesterol

There are different types of cholesterol - and not all cholesterol is harmful.

Can Exercise Lower Your Blood Cholesterol?

Being physically active can help lower your cholesterol level, whether it involves everyday activities like cleaning or gardening or a structured exercise program.

Featured Articles

Cholesterol News

What is a Hernia?

Hernia repair is one of the most common major operations performed in the United States. Every year, over one half million Americans undergo surgery for the treatment of this problem.

A hernia is a common ailment presently corrected by surgery in an outpatient surgery center or hospital. It can be congenital or traumatic origin. If not corrected, the hernia can incarcerate, followed by strangulation, which is a life threatening condition.

The most common of all hernias, the inguinal, occurs in the groin area. Protrusions elsewhere on the abdominal wall are called femoral and umbilical hernias. Highest up of all is the hiatal hernia, which occurs when part of the stomach pushes through the diaphragm separating the chest and the abdomen.

In the last decade of the nineteenth century, rapid advances in the knowledge of anatomy, surgical antisepsis, and anesthesia led to surgical treatment of hernias. Different methods of "layer closure" were devised during this period by surgeons in Italy, France and the United States.

The classic procedures developed by these surgeons formed the foundation of modern herniorrhaphy and they have been applied, essentially without significant alteration or improvement, for the past 100 years. However, even with this modification at the present time, the surgery carries a recurrence rate between 10% and 12%.

In 1940, Canadian surgeon Dr. E.E. Shouldice devised a new technique for hernia repair. The emphasis in the repair was based on the utilization of the transversalis fascia in an overlapping fashion. This method dramatically reduced the recurrence rate to 1.5% to 2%.

During the 1970's, Dr. Usher pioneered the use of polypropylene mesh in repair of abdominal wall hernias. Various methods of repair for all types of hernias began using this mesh.

In 1989, Dr. Robert M. Moran of our Institute combined the Shouldice technique with a preperitoneal insertion of a specialized polypropylene mesh manufactured by Ethicon© in repairing abdominal wall hernias. This concept has become the repair adopted by all surgeons at the National Ambulatory Hernia Institute with a resultant decrease of recurrence of these hernias to 0.4%.

In the last decade of the nineteenth century, there was a rapid advance in the knowledge of anatomy, surgical antisepsis, and anesthesia which led to the surgical treatment of the hernia.
During this time period, Dr. E Bassini in Italy, Dr. W.S. Halsted and Dr. A.H. Ferguson in the United States, and Dr. G. Lotheissen in France devised different varieties of layered closure for the defects remaining after sac ligation. These classic procedures form the foundation of modern herniorrhaphy and they have been applied essentially without significant alteration or improvement for over 100 years.

Today, most repairs of inguinal hernias are still based on these century-old techniques with recurrence rates of 10 to 12%. However, in 1940, Dr. E.E. Shouldice developed the multi-layer closure based on the transversalis fascia with recurrence rates of 1-1/2 to 2%.
In 1959, Dr. F.C. Usher introduced the use of polypropylene mesh in the repair of primary and recurrent hernias. This was followed by various mesh techniques.

Twenty-five years ago, the original description of the Shouldice hernia repair was published by Dr. Moran in a national surgical journal, Surgery. It was recognized as an important contribution by the Yearbook of Surgery. In 1988, the surgeons of the Hernia Institute combined these two procedures for our current repair. The principles of our repair are local anesthesia, a standard Shouldice dissection, and insertion of the Ethicon© polypropylene mesh beneath the transversalis fascia with a documented recurrence rate of 0.4% and warranty for a lifetime.

Appendectomy

Surgical removal of an inflamed or infected appendix (appendicitis).
Alternative names
Appendix removal

Description:
The appendix is a small, finger-shaped pouch of intestinal tissue located between the small intestine (cecum) and large intestine (colon). It is thought that blockage of the opening of the appendix into the bowel by a hard small stool fragment (fecalith) causes inflammation and infection of the appendix (appendicitis). The infected appendix then must be surgically removed (emergency appendectomy) before a hole develops in the appendix (perforation) and spreads the infection to the entire abdominal space (peritonitis).

The surgery is done while the patient is deep asleep and pain-free (using general anesthesia). A small incision is made in the right lower quadrant of the abdomen and the appendix is removed. If a pocket of infection (abscess) has formed or the appendix has ruptured (perforated), the abdomen will be thoroughly washed out during surgery and a small tube will be left in to help drain out fluids or pus.

Indications:
Infection or inflammation of the appendix (acute appendicitis). Symptoms of acute appendicitis include:

Your doctor will :

There is no test to confirm appendicitis and the symptoms may be caused by other illnesses. The doctor must diagnose from the information you report and what he sees. Even if the surgeon finds that the appendix is not infected (which can happen up to 25% of the time), he will thoroughly check the other abdominal organs and remove the appendix anyway.

Expectations after surgery:

Recovery from a simple appendectomy is usually complete and rapid. If the appendix has developed an abscess or ruptured, the recovery will be slower and more complicated, requiring use of medications to treat the infection (antibiotics).

Living without an appendix causes no known health problems.

Convalescence :

Convalescence is usually short and most patients leave the hospital in 1 to 3 days after the operation. Normal activities can be resumed within 1 to 3 weeks after leaving the hospital.

Risks
Risks for any anesthesia are:

Risks for any surgery are:

Additional risks for appendectomy that occurs with a ruptured appendicitis include:

Caution :
There are deaths annually in the U.S. from untreated acute appendicitis. If a person has symptoms of appendicitis (pain in the lower right abdomen, fever, loss of appetite, nausea, vomiting), DO NOT use heating pads, enemas, laxatives, or other home treatments. DO seek emergency healthcare promptly (your doctor or the emergency room).

Heart attack

A heart attack is when an area of heart muscle dies or is damaged because of an inadequate supply of oxygen to that area.

Alternative names
Myocardial infarction; MI; Acute MI
Causes, incidence, and risk factors

Heart attacks are often caused by a clot that blocks one of the coronary arteries (the blood vessels that bring blood and oxygen to heart muscle). The clot prevents blood and oxygen from reaching that area of the heart, leading to the death of heart cells in that area. Usually, this occurs in a coronary artery that has been narrowed from changes related to atherosclerosis. The damaged heart tissue permanently loses its ability to contract.

The risk factors for heart attack include:

A personal or family history of coronary artery disease, cerebrovascular disease, peripheral vascular disease, angina (particularly unstable angina), or kidney failure requiring hemodialysis also increase the risk for heart attack.
Occasionally, sudden overwhelming stress can trigger a heart attack, but this is rare. In older persons, straining to have a bowel movement can be a risk factor.

Newer risk factors for coronary artery disease have been identified over the past several years, including elevated homocysteine levels, elevated c-reactive protein, and apo-a. Homocysteine levels can be treated with folic acid supplements in the diet. Studies are still ongoing about the practical value of these new markers.

Chest pain is a major symptom of heart attack, but in many cases the pain may be subtle or even completely absent, especially in the elderly and diabetics. Other symptoms such as weakness, shortness of breath, nausea, or vomiting may predominate.

Heart attack accounts for 1 out of every 5 deaths. It is a major cause of sudden death in adults.

Prevention:

Control cardiac risk factors whenever possible. Control blood pressure and total cholesterol levels, reduce or avoid smoking, modify diet if necessary (increase high density lipoproteins and decrease low density lipoproteins), control diabetes, and lose weight if obese. Follow an exercise program to improve cardiovascular fitness. (Consult your health care provider first.)

After a heart attack, follow-up care is important to reduce the risk of developing a new heart attack. Often, a cardiac rehabilitation program is recommended to help you gradually return to a "normal" lifestyle. Follow the exercise, diet, and medication regimen prescribed by your doctor.

Symptoms:

Note :

The victim commonly denies that he or she may be having a heart attack. The person may have no symptoms (i.e., having a "silent attack")

Signs and tests :
Examination often reveals a rapid pulse. Blood pressure may be normal, high, or low. Listening to the chest with a stethoscope (auscultation) may show crackles in the lungs, heart murmur, or other abnormal sounds.

Heart attack and the extent of heart damage may also show on the following tests:

The by-products of heart damage and factors indicating high risk for heart attack may show on the following tests:

This disease may also alter the results of the following tests:

Sensorineural deafnessProvided by A.D.A.M.Overview | Images DefinitionAn irreversible type of hearing loss that occurs when cochlear sensorineural elements or the cochlear nerve is damaged in some way; it can progress to total deafness in the involved ear(s). Alternative namesNerve deafness

Alport syndrome

An inherited (usually X-linked) disorder involving damage to the kidney, blood in the urine, and in some families loss of hearing. The disorder may also include loss of vision.

Alternative names

Hereditary nephritis; Hematuria - nephropathy - deafness; Hemorrhagic familial nephritis; Hereditary deafness and nephropathy

Causes, incidence, and risk factors :
Alport syndrome is very similar to hereditary nephritis. There may be nerve deafness and congenital eye abnormalities associated with Alport syndrome. The cause is a mutation in a gene for collagen. The disorder is uncommon, affecting about 2 out of 10,000 people.

In women, the disorder is usually mild, with minimal or no symptoms. Women can transmit the gene for the disorder to their children even if the woman has no symptoms of the disorder. In men, the symptoms are more severe and progress faster.

The disorder causes chronic glomerulonephritis with destruction of the glomeruli. Initially, there are no symptoms. Progressive destruction of the glomeruli causes blood in the urine and decreases the effectiveness of the kidney's filtering system. There is progressive loss of kidney function and accumulation of fluids and wastes in the body, with eventual progression to end-stage renal (kidney) disease at an early age. ESRD caused by Alport syndrome often develops between adolescence and age 40.

Risk factors include having a family history of Alport syndrome, nephritis, end-stage renal disease in malerelatives, hearing loss before age 30, bloody urine, glomerulonephritis, and similar disorders.

Prevention
This uncommon disorder is inherited. Awareness of risk factors, such as a family history of the disorder, may allow the condition to be detected early.

Symptoms

Note:

There may be no symptoms in some cases. Symptoms of chronic renal failure or heart failure may be present or may develop.

Signs and tests :

Examination is nonspecific except for blood in the urine. Minute amounts of blood (microscopic hematuria) is present from birth in nearly all affected males. The blood pressure may be elevated. Examination of the eyes may show fundus (posterior inner part of eye) or lens changes, cataracts, or lens protrusion (lenticonus). Examination of the ears shows no structural changes.

Hearing loss

Hearing loss is the total or partial inability to hear sound in one or both ears.

Alternative names
Decreased hearing; Deafness; Loss of hearing

Considerations
Prevention of hearing loss is more effective than the treatment.

Minor decreases in hearing, especially of higher frequencies, are normal after age 20. Some nerve deafness (or loss of hearing) affects 1 out of 5 people by age 55. It usually comes on gradually, and it rarely ends in complete deafness. See hearing loss of aging. Alzheimer's disease or other neurological problems may sometimes be falsely suspected in older people because they have hearing problems.

There are many causes of hearing loss. They may be grouped in several ways. One way divides causes into 2 categories:

Conductive loss occurs when the three tiny bones of the ear (ossicles) fail to conduct sound to the cochlea or when the eardrum fails to vibrate in response to sound because of some mechanical problem such as fluid in the ear or disruption of the ossicles.

Nerve loss occurs when the nerve is injured by physical or other means.
Conductive loss is often potentially reversible -- nerve loss is not.
Hearing problems may be the reason some children's speech develops slowly. Ear infections are the most common cause of temporary hearing loss in children. Screening for hearing loss is now being recommended for all newborns.

Common causes :
Genetic:

Congenital:

Infectious:

Occupational:

Any occupation with chronic exposure to loud noises on a continuous day-to-day basis can result in hearing loss due to nerve end damage. Increased attention to conditions in the work environment has markedly decreased the likelihood of work-related hearing loss. (See occupational hearing loss.)

Traumatic:

Toxic:

Other:

TEMPORARY (OR SOMETIMES PERMANENT) HEARING LOSS

Home care

Wax build-up can frequently be flushed out of the ear (gently) with ear syringes (available in drug stores) and warm water. Wax softeners (like Cerumenex) may be needed if the wax is hard and impacted.

Care should be taken when removing foreign bodies. Unless it is easily accessible, have your health care provider remove the object. Don't use sharp instruments to remove foreign bodies.

A hearing aid can be helpful in coping with hearing loss caused by nerve damage.
Call your health care provider if

Medical history questions documenting hearing loss in detail may include:

The physical examination will include a detailed examination of the ears.

Diagnostic tests that may be performed include:

Intervention:
A hearing aid or cochlear implant may be provided to improve hearing.

After seeing your health care provider:
If a diagnosis was made by your health care provider related to hearing loss, you may want to note that diagnosis in your personal medical record.