What Your Bloodwork Can Reveal About Your Health: Blood test results outside a normal range may be nothing to panic about--but occasionally they can signal illness.
Complete Blood Count A complete blood count (CBC) checks the levels of a range of components in your blood, including the number of red and white blood cells, and platelets (which aid blood clotting); hemoglobin (the red-colored protein inside red blood cells that carries oxygen); and hematocrit: the ratio of red blood cells to plasma (the fluid component of blood).
Mount Sinai geriatrician Patricia Bloom, MD, says that CBC results outside the normal range usually aren't anything to worry about, especially if you feel well and are not experiencing any symptoms. But in some cases, low or high counts do point to a problem. For example, a low red blood cell count, along with abnormal measures for hemoglobin and hematocrit, may indicate anemia, while high numbers for these components may point to heart disease, lung disease, or bone marrow disorders. "High counts also can result from dehydration due to medications, vomiting, and diarrhea," adds Dr. Bloom.
White blood cells are a part of the immune system, and high counts can point to underlying infection, inflammation, stress, and some endocrine disorders. It's also possible for a genetic causes and some medications to elevate white blood cell counts, while low counts are associated with inherited syndromes, some infections, chemotherapy drugs, nutritional problems, and some blood disorders. "High or low platelet counts may indicate an underlying health problem, but also can be a reaction to medication," Dr. Bloom notes. "You may need further tests to clarify the reason."
Lipid Panel This test measures the amount of cholesterol and triglycerides (fats) in your blood. "Your body needs cholesterol to maintain the health of your cells, but elevated levels--along with high triglycerides--are a risk factor for heart and blood vessel disease," Dr. Bloom explains.
The American Heart Association recommends that people age 20 or older have their cholesterol checked every four to six years, but if you have known cardiovascular issues or are taking cholesterol-lowering statin drugs, your doctor may recommend a lipid panel more frequently.
Metabolic Panel A basic metabolic panel (BMP) checks kidney function, blood sugar, and electrolytes (sodium, potassium, chloride, and bicarbonate). The latter play a vital role in many bodily processes, including your heart and brain function, and muscle contraction. "High blood sugar may signal diabetes," Dr. Bloom says. "Electrolyte levels can become unbalanced if you're dehydrated or take diuretics-used to treat high blood pressure--and can be associated with heart, brain, kidney, and lung disease."
A BMP also measures creatinine and blood urea nitrogen (BUN)--both are byproducts of kidney function and can shed light on how well your kidneys are working. Abnormal creatinine and/or BUN levels can be due to dehydration or medications, but also may be associated with kidney or liver issues, gastrointestinal bleeding, and heart failure.
A complete metabolic panel (CMP) includes everything in the BMP, plus calcium and several chemicals related to liver function, including bilirubin, three specific liver enzymes, albumin (a protein produced in the liver), and total protein. Abnormal levels may be due to poor nutrition, but also may be linked to infections, inflammation, and kidney/liver or blood problems. "Abnormal calcium levels may suggest a problem with the bones, the parathyroid gland, or kidneys, and also are associated with some cancers," Dr. Bloom adds.
Thyroid Panel The thyroid is a small gland situated in the neck just below the larynx. It produces hormones that control your metabolism, influencing everything from the speed at which you digest fats and carbohydrates, to your heart rate. As such, any problem with your thyroid can have extensive health consequences.
Your doctor will likely recommend thyroid function testing if you have a family history of thyroid disease or are experiencing symptoms that may be thyroid-related. Fatigue, weight gain, constipation, and increased sensitivity to cold are associated with an underactive thyroid. The classic symptoms of an overactive thyroid include weight loss, heat intolerance, rapid heart rate, tremor, and anxiety--however, about one-third of older adults present with unexplained weight loss, shortness of breath, or a trial fibrillation (an abnormal heart rhythm). Undiagnosed hyperthyroidism can lead to severe osteoporosis.
Testing Vitamin Levels Your doctor may recommend blood tests to assess your levels of vitamins B12 and D. Older adults are vulnerable to B12 deficiencies that can impact brain and nervous system function. "As you age, you produce less intrinsic factor, a stomach protein that helps the body absorb vitamin B12 from food," Dr. Bloom explains. "Seniors also have less stomach acid, which makes it harder to separate B12 from food, although they can still absorb it as a supplement." Poor B12 absorption also can occur due to thyroid disorders and gastric bypass surgery (see our July issue for more on the latter), and if you take certain medications, such as antacids or long-term proton pump inhibitors like omeprazole (Prilosec[R]).
High vitamin D levels are associated with a lower risk of some cancers, heart disease, and diabetes, and the vitamin also may boost bone strength. "Vitamin D is synthesized in the skin with exposure to sunlight," Dr. Bloom says. "If you're homebound your doctor may suggest a blood test to check your D levels."
Blood Tests to Assess Clotting People who take the blood thinner warfarin (Coumadin[R]) need a regular blood test--called the international normalized ratio (INR) test--to check how long it takes their blood to clot. Clotting times that are too long mean you are at risk of bleeding. Your doctor will use the results to adjust your medication dosage as needed.
PSA Testing Older men may be advised to undergo a blood test for prostate specific antigen (PSA), elevated levels of which can be a sign of prostate cancer. However, there is debate over whether men age 75 and older should have this test. "If your doctor recommends PSA testing, discuss with him or her the possible harms of prostate cancer screening," Dr. Bloom advises.
Try Not to Panic About Test Results
When several blood tests with several components each are performed, there is a very high statistical chance that one or more of the test results may be at least mildly abnormal. "Given this, along with the fact that there are many conditions that alter blood test results, you shouldn't panic," Dr. Bloom emphasizes. "Discuss the results with your doctor, and be fully involved in any decision about further tests."
WHAT YOU SHOULD KNOW
* You may need to stop certain drugs and dietary supplements before a blood test
Check with your doctor for clarification.
* If you are scheduled for a "fasting" blood test, you will need to stop eating about 12 hours before the test. You'll also need to avoid your morning coffee or tea-instead, drink water.
* Don't smoke before a blood test, as this can affect the results.
Caption: Your ratio of red blood cells to white is one of several important health indicators your bloodwork can clarify.
Caption: If you have a chronic health condition or take certain medications, you may need regular bloodwork to monitor your health.
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|Title Annotation:||FOCUS ON HEALTHY AGING|
|Publication:||Focus on Healthy Aging|
|Date:||Jul 24, 2019|
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