Blood Analysis
Blood analysis is a vital medical process that involves obtaining blood samples to evaluate the health of an individual. This testing provides insights into various aspects of health, including blood type and the quantity and quality of blood components. Blood analysis is often part of routine checkups or used to diagnose and monitor specific health conditions. It helps identify systemic issues and infectious diseases, allowing physicians to assess medication effectiveness and overall health.
The blood comprises red blood cells (erythrocytes), which transport oxygen, white blood cells (leukocytes), which fight infections, and platelets that assist in clotting. Plasma, the liquid portion of blood, contains nutrients and hormones essential for bodily functions. Blood tests can screen for conditions like high cholesterol, diabetes, and infections, and are crucial for evaluating organ function.
The analysis begins with drawing blood, usually from a vein or a fingertip, and the samples are sent to a laboratory for testing. Advanced technology like automated instruments is commonly used for analysis, although traditional methods such as microscopy and chemical treatments are also employed. Blood analysis continues to evolve, contributing significantly to modern medical diagnostics and treatment strategies.
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Blood Analysis
Blood analysis is a process of procuring blood samples and testing them. This testing can help provide information on the relative health of the subject, including the blood type, quantity and quality of various components of the blood, and the health of other systems in the body. Blood analysis can be done as part of a routine medical checkup or to diagnose and monitor a health condition. These tests can aid in identifying systemic problems and infectious diseases and help physicians determine if medications are working properly.
Background
Blood is a liquid that travels throughout the body, delivering oxygen and nutrients to cells and carrying away waste from the cells. Blood makes up about 40 percent of the body and is essential to life in many ways. Therefore, knowing about the state of the components of a person's blood can tell a physician a great deal about that person's health. This is accomplished through blood analysis, which is often called blood testing.
There are three main types of blood cells, which are manufactured in bone marrow. Erythrocytes, or red blood cells, contain hemoglobin. This chemical transports oxygen throughout the body. The body needs many red blood cells, and millions are manufactured each day. Leukocytes, or white blood cells, are part of the body's system for fighting infection. There are a number of different types of white blood cells, including neutrophils, lymphocytes, eosinophils, monocytes, and basophils. These cells identify and attack infections such as germs and viruses. Some of them also produce antibodies that help the body fight future infections of the same germ or virus. Platelets are the part of the blood that helps it clot, turning into a semisolid form that prevents the person from bleeding too much after a cut or other injury.
The remainder of blood—about 60 percent of it—is made of plasma. Plasma is mostly water with a variety of nutrients and other substances the body needs. These include salts, glucose (sugars), fats, antibodies, hormones, and enzymes.
Blood is pushed through the body by the activity of the heart. Blood travels through arteries, veins, and vessels to the lungs, where the blood collects oxygen. The heart then pumps the blood to all parts of the body before returning to the heart. Along the way, the blood picks up other nutrients for delivery to different parts of the body and picks up waste products that are then delivered to the liver and kidneys for disposal.
Physicians discovered the blood circulation process in the mid-1600s, and by 1658, Dutch biologist Jan Swammerdam identified red blood cells. Doctors began human blood transfusions—taking blood from one person and placing it in the system of another—shortly thereafter. However, it would be 1901 before Austrian physician Karl Landsteiner determined that blood had "types" and devised a blood test that improved the likelihood the transfusion would succeed. Biologists and physicians have developed many different blood tests that can determine a person's health, and new tests continue to be developed into the twenty-first century. These tests include complete blood count (CBC) tests; tests to measure cholesterol, glucose, and oxygen content of the blood; electrolyte testing; and tests that help measure the function of the heart, liver, thyroid, and other body systems. Blood tests can also identify antibodies, viruses, germs, certain types of cancers, and other items that help with the diagnosis and treatment of illnesses.
Overview
Blood tests can be ordered for a number of different reasons. When completed as part of a routine physical, the tests can help the doctor determine if there are any hidden health issues or potential problems that need treatment. For example, when a person has too much of a certain kind of fat called cholesterol in the blood, it does not cause any physical symptoms but can cause damage to the heart and blood vessels; testing the blood for cholesterol will identify this potential problem. When a person presents with symptoms of illness, blood tests can help the physician determine the nature of the problem. For instance, a person with a high fever and fatigue can have any number of infectious conditions, and a physician can often determine the source of the infection with a blood test. Blood tests can determine how much and what types of waste material are circulating in the blood, providing the physician with clues as to the health of the kidneys and liver. Physicians who prescribe certain medications can also use blood tests to see how much of the medication is circulating in the blood and gauge its effectiveness. Blood tests are also used to determine what blood type a person has so the right type of blood can be given in an infusion. Other common blood tests include those used to determine how well blood clots, to check thyroid function, to test for inflammation in the body, and to look for antibodies to various germs or viruses.
The process of analyzing blood begins with extracting a blood sample. This can be done by using a needle inserted into a vein to draw blood into a vial, or by picking a finger, heel, or other body part to draw a smaller blood sample. Most blood tests are done on blood collected in vials. However, some tests can be done with a much smaller blood sample. These include tests to monitor diagnosed diabetes or to check a newborn baby for phenylketonuria (PKU), an inherited problem in how the body metabolizes a specific amino acid. More rarely, blood may be drawn directly from an artery. Some tests require that the patient refrain from eating for a period beforehand. The drawn blood is then labeled and packed to protect it, and sent to a laboratory for testing.
The laboratory will use various procedures to test the blood. By the 2020s, an automated instrument was most often used to analyze blood samples. However, other methods also existed. These included looking at a small amount under a microscope or treating some of the blood with different chemicals. Sometimes the blood was separated into different parts. This was often done with a centrifuge, which spun the vial containing the sample at a high rate of speed. It could also be done with chemicals to cause parts of the blood to coagulate, or clot, or by simply letting the sample stand until the parts separate on their own.
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