HEALTH SCREENING PROCEDURES
Cholesterol
Cholesterol is naturally produced by the liver, and helps carry fat to parts of the body that need it for energy and repairs. Cholesterol is a soft, waxy substance found among the lipids (fats) in the bloodstream and in all the body's cells. It is normal to have cholesterol. It's an important part of a healthy body because it is used to form cell membranes, some hormones, and serve other needed bodily functions. But too high a level of cholesterol in the blood is a major risk for coronary heart disease, which leads to heart attack. It is also a risk factor for stroke.
When cholesterol rises above a desirable level, it may build up in the body and may put a person at increased risk for heart disease or stroke. Hypercholesterolemia is the term for high levels of blood cholesterol.
A person gets cholesterol in two ways. The body makes some of it, and the rest comes from animal products that are eaten, such as meats, poultry, fish, eggs, butter, cheese, and whole milk. Food from plants like fruits, vegetables, and cereals do not have cholesterol.
Cholesterol and other fats can't dissolve in the blood. They have to be transported to and from the cells by special carriers called lipoproteins. There are two kinds that a person needs to be concerned with. Low-density lipoprotein, or LDL, is known as the "bad" cholesterol. Too much LDL cholesterol can clog the arteries to the heart and increase the risk of heart attack. High-density lipoprotein, or HDL, is known as the "good" cholesterol. The body makes HDL cholesterol for its protection. It travels away from the arteries. Studies suggest that high levels of HDL cholesterol reduce the risk of heart attack.
High cholesterol is one of the main risk factors for coronary heart disease that a person can control. Periodic screening for high blood cholesterol is recommended for all men starting at age 35 and women starting at age 45. Some believe that all adults age 20 and over should have their cholesterol measured periodically.
Coronary heart disease is the leading cause of death in America today. Elevated levels of cholesterol play a significant role in as many as 50% of those deaths. Although high cholesterolis a serious risk factor for heart disease, it can be modified. There are several drugs on themarket today to assist in lowering cholesterol levels.
Prostate-Specific Antigen (PSA)
Prostate-specific antigen (PSA) is a protein produced by the cells of the prostate gland. The PSA blood test measures the level of PSA present in the blood. When the prostate gland enlarges, PSA levels in the blood tend to rise. PSA levels can rise due to cancer or benign (non-cancerous) conditions. Because PSA is produced by the body and can be used to detect disease, it is sometimes called a biological marker.
The PSA test does not give physicians enough information to distinguish between a benign or cancerous condition, but the physician will take the test as an indication of a pending condition and then can order further testing.
The U.S. Food and Drug Administration (FDA) has approved the PSA test to be used in addition to a digital rectal exam to help detect prostate cancer in men ages 50 and older. It is also approved to monitor patients with a history of prostate cancer to check for reoccurrence.
Benefits from screening for prostate cancer are still being studied. Testing is currently being done by the National Cancer Institute (NCI) to determine if certain screening tests reduce the number of deaths caused by prostate, lung, colorectal, and ovarian cancer. Using the PSA test to screen men for prostate cancer is controversial because it is not yet known if the process actually saves lives.
Recommendations for screening vary. Some encourage yearly screening for men ages 50 and over. Others recommend against routine screening, and still others counsel men individually about the risks and benefits of screening and leave the decision to the patient. These patients should be informed of the risk factors that increase a man’s chances of developing prostate cancer.
The most common risk factor is age. More than 96% of prostate cancer cases occur in men ages 55 and older. Other risk factors for prostate cancer include a family history and race. Men who have a father or brother with prostate cancer have a greater chance of developing prostate cancer. African American men have the highest rate of prostate cancer, while Native American men have the lowest.
No screening test is without its limitations. Even though the PSA test can detect small tumors, it does not necessarily reduce the chance of death from prostate cancer. The PSA test indicates a tumor is present, but does not identify what kind of tumor, slow growing or aggressive. False positive tests can occur when the PSA level is elevated and no cancer is actually present. There can also be false negative tests when the PSA range is normal, even though prostate cancer is present. This is why research continues to improve the PSA test.
Mammograms
A screening mammogram is an x-ray of the breast used to detect changes in women who have no signs or symptoms of breast cancer. It usually involves two x-rays of each breast. With a mammogram, it is possible to detect microcalcifications (tiny deposits of calcium in the breast, which sometimes are a clue to the presence of breast cancer) or a tumor that cannot be felt.
A diagnostic mammogram is an x-ray of the breast that is used to diagnose unusual breast changes, such as a lump, pain, thickening, nipple discharge, or a change in breast size or shape. A diagnostic mammogram is also used to evaluate changes detected on a screening mammogram. A diagnostic mammogram takes longer because it involves more x-rays to obtain more views.
The National Cancer Institute (NCI) recommends that women have a screening mammogram every 1 to 2 years when they are in their 40s and older. Women who are at higher than average risk of breast cancer should talk to their health care providers about whether to have mammograms before age 40 and how often to have them. The risk of developing breast cancer is not the same for all women.
Research has shown that several factors increase a woman’s chance of developing breast cancer. Some of these factors include personal history of breast cancer; family history; certain breast changes on biopsy; genetic alterations; reproductive and menstrual history; breast density; radiation therapy; diet, and lifestyle factors. Refer to the National Cancer Institute web site for more information.
Age is the most important risk factor for breast cancer. The older a woman is, the greater her chance of developing breast cancer. Most breast cancers occur in women over the age of 50; the number of cases is especially high for women over age 60 and is relatively uncommon in women under the age of 40.
Even though several studies have shown that screening mammograms have reduced the number of deaths from breast cancer, every woman should perform self-breast exams on a routine basis. Breast self-exams (BSE) alone reduce the numbers of deaths from breast cancer every year. BSE should not take the place of a clinical breast exam by a health care provider and a mammogram. Mammograms can detect breast cancer that cannot be felt.
Even though mammography can detect tumors that cannot be felt, finding a small tumor does not always mean that a woman’s life will be saved. Mammography may not help a woman with a fast-growing or aggressive tumor that may have spread to other parts of her body before being detected. There are also false positive and false negative reports. Overall, mammograms miss up to 20 percent of all breast cancers that are present at the time of screening.
Pap Test
The Pap test (sometimes called a Pap smear) is a way to examine cells collected from the cervix, which is the lower, narrow end of the uterus. This test can show the presence of infection, inflammation, abnormal cells, or cancer. The Pap test is performed during a pelvic exam. During a pelvic exam, an instrument called a speculum is used to widen the vagina so the cervix can be seen. Another instrument is used to obtain the sample of cells from in and around the cervix. The specimen (or smear) is placed on a glass slide, treated with a fixative, and sent to a laboratory for examination.
A Pap test and pelvic exam are important parts of a woman’s routine health care. They can detect abnormalities that may lead to invasive cancer. These abnormalities can be treated before the cancer develops. Most invasive cancers of the cervix can be prevented if women have Pap tests and pelvic exams regularly. Women are encouraged to visit their physician or other specially trained health care professional, such as physician assistants, nurse midwife or nurse practitioner, who may perform Pap tests and pelvic exams.
Current guidelines recommend that women who are or have been sexually active, or have reached age 18, should have Pap tests and pelvic exams regularly. There is no known age at which Pap tests cease to be effective. Yearly Pap tests and pelvic exams are recommended. A woman should have the Pap test when she is not menstruating. The best time is between 10 and 20 days after the first day of the last menstrual period.
About 50 million Pap tests are performed each year in the U.S. Five to seven percent of these are reported as abnormal. An abnormal result may mean that the cells on the surface of the cervix appear abnormal but are not necessarily cancerous. Some abnormal conditions may lead to cancer but many do not. There are several classifications of abnormal findings. These describe abnormal changes to cells on the surface of the cervix.
As with any screening test, there can be false positive and false negative results. False positive and false negative results do not occur very often, but they can cause anxiety and can affect a woman’s health. Regular screening helps to compensate for the false negative results. In 1996, the National Institute of Health (NIH) concluded that about half of the false negative Pap tests were due to inadequate specimen collection. The other half were caused by a failure to identify or interpret the specimens correctly. As a result of these conclusions, new methods of collecting and reading cervical cells have been developed.
Colorectal Cancer Screening
Colorectal cancer is a disease in which cells in the colon or rectum become abnormal and divide without control or order, forming a tumor. Cancer cells invade and destroy the tissue around them. They also break away from the tumor and spread to form new tumors in other parts of the body.
Colorectal cancer is the fourth most common type of cancer and the second leading cause of cancer death in the U.S. Although the numbers are decreasing, 135,000 new cases are diagnosed and more than 56,000 people die from colorectal cancer each year.
The exact causes of colorectal cancer are unknown. However, studies show that there are certain factors that increase a person’s chance of developing this cancer. One factor is age; colorectal cancer is more likely to occur as people get older. Other factors are the presence of polyps (benign growths); personal history of colorectal cancer or other cancers; family history of colorectal cancer; ulcerative or Crohn’s colitis; and diet. This cancer may be associated with a diet high in fat and low in fiber.
Screening for colorectal cancer involves checking for health problems before they cause symptoms. Several procedures are used in screening for colorectal cancer. A fecal occult blood test (FOBT) checks for hidden blood in the stool. Studies have proven that the FOBT, when performed every 1 to 2 years in people ages 50 and over, can reduce the number of deaths from colorectal cancer.
Another screening method is a sigmoidoscopy, which is an examination of the rectum and lower colon using a lighted instrument called a sigmoidoscope. A colonoscopy is an examination of the rectum and entire colon using a colonoscope. Both of these examinations can find precancerous or cancerous growths in the scoped area. The colonoscopy has increased risks of bleeding and puncturing the lining of the colon. Studies suggest that regular screening with sigmoidoscopy after age 50 can reduce the numbers of deaths from colorectal cancer.
The American Cancer Society and the U.S. Preventative Services Task Force have developed guidelines for colorectal screening. Although their recommendations vary for which screening tests to use and how often to screen, all of the organizations support screening for colorectal cancer. People should talk with their health care provider about when and how to screen. Decisions will be made according to the risk factors present.
Skin Cancer Screening
Skin cancer is the most common cancer in the United States. It affects one million Americans each year. Skin cancer accounts for about 2% of all cancer deaths. Nearly all skin cancers occur in fair-skinned individuals who have been exposed to the sun, x-rays, or ultraviolet light for extended periods.
There are three main types of skin cancer: basal cell, the most common; squamous cell; and malignant melanoma. Basal and squamous cell cancers have an excellent prognosis, but individuals with nonmelanoma skin cancer are at a higher risk for developing additional skin cancers.
Skin cancers are easily detected clinically and are often cured by excisional biopsy. That does not mean that they should be neglected, because when neglected, they can be very deforming and may cause death. Melanoma, the least common and most deadly, is responsible for about 75% of all deaths from skin cancer. Most research and studies are based on the melanoma cancers.
Fair-skinned persons exposed to the sun are at a higher risk for skin cancer. The incidence of melanoma rises rapidly in Caucasians after age 20. The best defense is protection from ultraviolet light. Incidence increased 126% between 1973 and 1995 in the U.S., while mortality rates of melanoma increased by 1.7% annually between 1973 and 1990. In the 90s the incidence rates stabilized and the mortality rates decreased slightly, possibly due to the trend of prevention and early detection.
In 2002, about 53,600 individuals are expected to develop melanoma and almost 7,400 to die. Screening is the key to early detection. Over 90% of melanomas that arise in the skin can be recognized with the naked eye. Very often there is a prolonged horizontal growth phase where the tumor expands beneath the epidermis but does not invade the dermis. Melanoma is 100% curable if treated prior to the onset of the vertical growth phase with its metastatic potential.
People are asked to observe their skin and note any changes. A visit to the dermatologist for a full screening provides a good baseline. This is an individual decision based on skin type, personal history, and family history. Use of sunscreens in prevention of melanoma has been challenged in several studies. The best prevention is limited exposure to the sun and ultraviolet light.
Screening for VisionProblems
Snellen Charts
- Come in a variety of types
- Some contain pictures for small children
- Some have E in various positions (Pt. points in direction of E) for non-English speaking people or non-readers
- Some contain letters of the alphabet
- Characters (letters or pictures) on the chart come in specific heights - smallest at bottom of chart.
NORMAL VISION = 20/20
- When standing 20 feet from the chart, a person should be able to see characters 20 mm high
- The top number represents the distance from the chart.
Snellen charts test only for myopia.
To test for hyperopia, a printing book or cards are used.
Color blindness is usually tested using the Ishihara method
Vision Screening Terms and Abbreviations
O.D.Right Eye
O.S.Left Eye
O.U.Both Eyes
MyopiaNearsighted, defect in distance vision
HyperopiaFarsighted, defect in close vision
OphthalmoscopeInstrument for examining the eye
TonometerInstrument to measure intraocular pressure --sign of glaucoma