Those dreaded words…”we’ll need to do a blood test…..” set many of you into a panic, but trust me, doctors love blood tests. Not in a vampirish way, but in a scientific way, because many mysteries of the body are revealed by examining this essential red fluid. Blood analysis is one of the most helpful tools in modern medicine.
Blood is the great delivery system of the body. It is a mixture of cells and a fluid called plasma. Red blood cells, which derive their color from their iron content, absorb and bind oxygen as they pass through the lungs and later release it into oxygen-needing tissues. They then bring carbon dioxide from those tissues back to the lungs to be exhaled. White cells are delivered to areas of the body that have been invaded by irritants or infections and help limit the intrusion. Yet another type of cells, platelets , are deposited by the blood into the areas of leakage, where clotting is needed. Platelets pile up one upon the other, likes plates in the sink, to plug up the breach.
Plasma is what is left of blood if all the cells are removed. Plasma is replete with nutrients, such as protein, glucose, and vitamins, that are indispensable to the function of each and every cell. It is the conduit for hormone delivery, carrying thyroid and adrenal and reproductive hormones from the parent gland to the target organs.Life-sustaining minerals, such as potassium and sodium and chloride, are transported via plasma to assure proper levels in every body system.
Blood was recognized as a critical body component in ancient times, but it wasn’t until 1628 that the father of cardiology, William Harvey, discovered that it was pumped by the heart and circulated throughout our body. Within 50 years, the first blood transfusion was attempted. But it was not until 1892 that the great statesman of modern medicine, Sir William Osler, described the utility of routine blood testing. InitIally, these examinations were extremely basic and noted only the amount of cells, but within 10 years a way to “type” the blood and thereby dramatically improve the success of transfusions was developed. There has been a continual stream of development in the field of blood analysis since then, with an ever growing number of ways the science of blood can improve health.
The innumerably helpful effects of blood tests can be divided into 4 main categories: (1)improving the safety of blood transfusion (2) diagnosing disease (3) monitoring the safety and efficacy of medical treatment and (4)detecting the risk of future disease.
While most of us will be lucky enough to avoid transfusion during our lifetimes, we all potentially benefit from the improved ability of blood banks to screen and type their supply. Routine analysis now dramatically reduces the risk of adverse reaction during the transfusion, or of contracting such blood born diseases such as syphilis, hepatitis and HIV.
Since they were first developed, blood tests have been invaluable tools in disease diagnosis. Initially, by evaluating blood counts, physicians were able to identity overwhelming infection (by high white counts) and anemia (low red cell count). Shortly thereafter, clotting disorders such as hemophilia were able to be clearly detected. Then, excessive sugar in the plasma was found to reveal diabetes sooner and more reliably than the traditional urine tests. Now, the brief discomfort of venipuncture can help your doctor detect thousands of conditions, ranging from lyme disease to thyroid imbalance. Heart attacks, liver and kidney problems, vitamin deficiencies–all can be recognized definitively, thus allowing essential therapy to be started.
Laboratory analysis is also vital to guide and track medical treatment. Drugs used to treat disorders such as epilepsy and rheumatoid arthritis are toxic if administered in excess; blood levels help practitioners determine the proper dose. Blood thinner treatment with the medication Coumadin (warfarin), is rendered incalculably safer by an exam called an INR, that can be performed with a drop of blood from a fingerstick. Cholesterol medication protocols are guided by blood examination to ensure that this blood fat is properly reduced without straining the liver. These are just a few examples of how a doctor’s care is made safer by blood testing.
Predicting future health, and enabling risk reduction and early treatment has become a preeminent role of blood analysis. Cholesterol levels can determine one’s risk of future heart attack and stroke, allowing individuals to seek advice regarding risk reduction. A D-Dimer level is a blood test done in the emergency room indicating risk of blood clots. Genetic tests can reveal risks of cancer, blood clots and dementia. DNA analysis, in fact, has become one of the most exciting frontiers in medical science.
So blood, that vital fluid without which we cannot live, can reveal much about ourselves, including our present and future health. Don’t begrudge your doctor a few milliliters to ensure your wellness. And if you fear you have, or may have, an illness, don’t hesitate to talk to your doctor about getting a blood test. It could save your life.