Blood Test
A sample of your blood can provide many clues about the quantity and quality of the individual blood cells and whether your blood can clot normally. To obtain a sample of your blood, a medical technician will draw blood with a needle and syringe from your forearm and send it to a laboratory. At the laboratory, your blood will be analyzed in several ways. Tests will be done to check the number of your red blood cells and the concentration of hemoglobin inside them. Hemoglobin is the substance in red blood cells that carries oxygen throughout the body. A low red blood cell count or too little hemoglobin indicates anemia. Blood tests also will be conducted to detect the number of white blood cells, which have a major part in defending the body against infection. If an infection is present, the number of white blood cells in your blood will rise. The appearance of your blood cells is also important. Abnormally shaped red or white blood cells can signal the presence of diverse conditions such as sickle-cell disease, leukemia, or mononucleosis. Finally, your blood will be checked to see how well it clots by examining the number of blood cells called platelets, which help stop bleeding.
Cholesterol Levels Elevated levels of the fats known as cholesterol in your blood increase your risk for heart disease. When the excess fats build up inside the walls of your arteries, they narrow the arteries, obstructing blood flow to your heart. When the heart receives less blood, it gets less oxygen, which is transported by red blood cells. Your heart sends out warning signals in the form of pain and discomfort known as angina. When the blockage in the arteries supplying blood to your heart causes severe obstruction, resulting in a heart attack, the heart muscle can become permanently damaged.
Cholesterol comes in two forms: low-density lipoprotein (LDL), the “bad” cholesterol, and high-density lipoprotein (HDL), the “good” cholesterol. Somewhat like a delivery truck, LDL cholesterol carries most of the fat in your blood and deposits the excess inside your artery walls. Like a garbage truck, HDL cholesterol removes fat from your blood, preventing it from building up in your arteries. When testing your cholesterol levels, your doctor measures your total blood cholesterol as well as your LDL and HDL levels by taking a sample of your blood and having it analyzed in a laboratory. A desirable total blood cholesterol level falls under 200 milligrams per deciliter of blood. Doctors consider cholesterol levels above 200 to be high. One in five Americans has a total cholesterol level of 240 or greater, placing that person at risk of a heart attack. Your LDL cholesterol levels should be under 100,
and HDL levels should be 40 or higher. The higher your HDL level, the lower your risk for heart disease. All men over 20 years of age should have their total cholesterol levels checked at least once every 5 years. Your level of LDL cholesterol also should be tested if your HDL is less than 40 or if your total cholesterol is 240 or higher—200 if you have two or more risk factors for heart disease. Talk to your doctor about your personal risk factors for heart disease. Don’t hesitate to ask him or her anything you do not understand about cholesterol testing.
Urinalysis
Your urine provides crucial information about the presence of any disorders of the kidneys or bladder. If your doctor orders a urinalysis, you will be asked to pass some urine and collect a midstream sample (urinate for several seconds before collecting the sample of urine) in a small container, either at home or in the doctor’s office. If you are uncircumcised, you should pull back your foreskin and wash the tip of your penis with soap and water before urinating to ensure that your urine remains sterile. Your urine may be tested in a laboratory or in the doctor’s office, using special strips that the doctor can dip into the urine to test for any abnormalities. The presence of particular substances such as blood or
sugar in the urine can indicate certain diseases. For example, the presence of protein in the urine can signal some types of kidney disease.
X ray
The most common scanning test is the X ray, in which electromagnetic radiation passes through a body part to produce a picture of internal structures on film. X rays are a good way of showing dense areas of the body, such as bones or a tumor, that allow only a few rays to pass through. These dense areas show up as white areas on the film. Doctors use X rays to examine the chest, skull, and spine
and to view a bone that may have been fractured. Even organs filled with fluid, gas, or air—such as the arteries, colon, or bladder—can be viewed with X rays if the organs are first enhanced with a special liquid dye called a contrast medium. The contrast medium is injected, swallowed, or inserted through the anus; then the doctor or technician takes a series of X rays as the contrast medium moves
through the organ to facilitate viewing. Getting an X ray is safe because today’s X-ray equipment minimizes your exposure to radiation.
MRI
Magnetic resonance imaging (MRI) uses a magnetic field and radio waves to produce a picture of the inside of the body. When you undergo an MRI, you lie on a table that slides into a rounded scanner containing a doughnut-shaped magnet that creates a magnetic field. Radio waves are sent to the part of your body to be viewed. The atoms in your body respond by emitting energy, and a magnetic field detector measures this energy and sends it to a computer, which translates the signal and creates a picture that your doctor can read. The procedure can take from 30 to 90 minutes and is painless, but the magnetic field can interfere with a pacemaker, hearing aid, or metal implants, so your doctor needs to know if you have any of these devices in your body. MRI scanning poses no known health risks.
Ultrasound
Ultrasound scanning uses sound waves to produce pictures of internal body structures. Doctors often use an ultrasound scan to diagnose disorders of the heart, kidneys, bladder, gallbladder, and pancreas. If your doctor orders an ultrasound scan, you will be asked to lie on a table, and the ultrasound technician will spread a gel on your skin over the area to be scanned. The technician will then move a handheld instrument called a transducer over the area, sending sound waves into your body. The sound waves bounce off of your internal organs, and the transducer transforms the waves into an image on a screen or on paper. Ultrasound is risk-free and is not painful.
CT Scan
Computed tomography (CT) scans take hundreds of X-ray images of the body from different directions that a computer then converts into cross-sectional pictures on a screen. CT scans can pick up details of abnormalities that a conventional X ray cannot detect. Doctors often order a CT scan to check for tumors or other abnormalities in the brain, liver, spleen, lungs, kidneys, pelvis, or lymph nodes (a part of the body’s immune system). During a CT scan, you lie on a table that moves into a circular machine. A tube revolves around the machine, taking multiple, low-dose X-ray images from many angles. The procedure takes about 20 minutes. Although a CT scan takes a vast number of images, the amount of radiation generated in a CT scan can be the same as or even less than that from a traditional X ray.
