Amniocentesis: What you really need to know
All About Blood Tests
Blood tests can be used to help a doctor identify a variety of health conditions, including infections, anemia, high cholesterol, vitamin deficiencies, organ failure, HIV, cancer, diabetes, and more.
Regular blood testing is one of the most important ways to keep track of your overall physical well-being. Getting tested at routine intervals can allow you to see the way your body changes over time and empower you to make informed decisions about your health.
What does a blood test show?Some blood tests can help your doctor determine how different organs in your body are working. Examples of organs whose malfunctions can be visible in a blood test include your heart, thyroid, liver, or kidneys.
Your doctor can also use blood tests to search for markers of diseases and health conditions such as:
Even if a person does not have heart disease, a blood test can show whether they may be at risk of developing the condition.
Other blood tests can indicate whether the medications you're taking are working properly, or assess how well your blood is clotting.
Let's take a closer look at some common blood tests.
1. Complete blood countA routine complete blood count (CBC) checks for levels of 10 different components of every major cell in your blood: white blood cells, red blood cells, and platelets.
Important components this test measures include red blood cell count, hemoglobin, and hematocrit.
Here's the typical range of results, although every laboratory may have its own range that varies slightly:
Abnormal levels of these components may indicate:
Based on your results, your doctor will order follow-up tests to confirm abnormal levels and a possible diagnosis.
2. Basic metabolic panelA basic metabolic panel (BMP) usually checks for levels of eight compounds in the blood:
This test may require you to fast for at least 8 hours before your blood is drawn, depending on the instructions of your doctor and what the test is measuring.
See our chart for normal results.
Abnormal results may indicate:
Your doctor will perform follow-up tests to confirm a diagnosis.
3. Comprehensive metabolic panelA comprehensive metabolic panel (CMP) includes all the measurements of a BMP as well as additional proteins and substances related to liver function, such as:
The same conclusions can be drawn from a CMP as from a BMP for the same substances that a BMP covers. Other abnormal levels can also indicate underlying conditions, such as:
4. Lipid panelThis test checks levels of two types of cholesterol:
HDL is "good" because it removes harmful substances from your blood and helps the liver break them down into waste. LDL is "bad" because it can cause plaque to develop in your arteries, increasing your risk of heart disease.
You may need to fast for at least 8 hours before this test.
For HDL cholesterol, 60 mg/dL or above is considered to be heart-healthy, while under 40 mg/dL is a major risk factor for heart disease.
For LDL cholesterol, 100 mg/dL or below is optimal for good health, while 160 mg/dL or over is dangerously high.
Normal levels can also vary by age.
5. Thyroid panelA thyroid panel, or thyroid function test, checks how well your thyroid is producing and reacting to certain hormones, such as:
Your thyroid is a tiny gland in your neck. It helps regulate bodily functions like your mood, energy level, and overall metabolism.
Here are normal results:
Abnormal levels of these hormones can indicate numerous conditions, such as:
6. Cardiac biomarkersEnzymes are proteins that help your body accomplish certain chemical processes, such as breaking down food and clotting blood. They're used throughout your body for many vital functions.
Abnormal enzyme levels can indicate many conditions.
Common enzymes tested include:
Here are the normal ranges for the enzymes listed above:
Many sexually transmitted infections (STIs) can be diagnosed using a blood sample. These tests are often combined with urine samples or swabs of infected tissue for more accurate diagnoses.
The following STIs can be diagnosed with blood tests:
Blood tests aren't always accurate right after contracting an infection. For an HIV infection, for example, you may need to wait at least a month before a blood test can detect the virus.
8. Coagulation panelCoagulation tests measure how well your blood clots and how long it takes for your blood to clot. Examples include the prothrombin time (PT) test and fibrinogen activity test.
Clotting is a crucial process that helps you stop bleeding after a cut or wound. But a clot in a vein or artery can be deadly since it can block blood flow to your brain, heart, or lungs. This can cause a heart attack or stroke.
Coagulation test results vary based on your health and any underlying conditions that may affect clotting.
Results from this test can be used to diagnose:
9. DHEA-sulfate serum testThe dehydroepiandrosterone (DHEA) hormone comes from your adrenal glands. This test measures whether it's too high or too low.
In men, DHEA helps develop traits like body hair growth, so low levels are considered abnormal. In women, high levels can cause typically male traits, like excess body hair, to develop, so low levels are normal.
Low levels may be caused by:
High levels in men or women can result from:
10. C-reactive protein testC-reactive protein (CRP) is made by your liver when tissues in your body are inflamed. High CRP levels indicate inflammation from a variety of causes, including:
The higher the level, the higher the risk of heart disease:
How often you should get a physical exam may depend on your age, according to guidelines from a variety of clinical organizations:
Your doctor will decide whether you need any blood tests during your physical exam.
In general, recommendations call for at minimum a lipid test starting at age 20 and every 5 years after that for people with a low risk of heart disease.
For people at a higher risk of heart disease, more frequent lipid testing may be necessary.
In addition, you should get a blood glucose test if your are between 40 and 70 years old and overweight or have obesity. People over age 45 should get a fecal occult blood test to screen for colorectal cancer annually.
But some doctors may still suggest routine blood work during your yearly physical exam, and in some cases, you may want to get additional testing. For example, when:
Talk with your doctor first if you want to get certain tests done, or have them done more often than once a year.
Who orders my blood tests?Your doctor typically orders blood tests for you during a physical, checkup, or an appointment intended to screen for a specific condition.
It's possible to order your own blood tests without a doctor through laboratories like LabCorp and Quest Diagnostics, but health insurance may not cover these tests.
While such blood tests may more accessible and convenient, it may be harder to interpret the results without a medical professional.
Some blood testing facilities may also not give you accurate results.
One infamous case of this is Theranos. The California biotechnology firm shut down in 2018 when an investigation uncovered lies and fraud around the accuracy of its private blood-testing technology.
Currently, litigation is underway against the founder and chief executive of the company, Elizabeth Holmes.
Where can I get blood work done?There are different locations that offer laboratory services that include blood work. Most hospitals contain a laboratory that you can visit to get tests done. Some laboratories will have walk-in options. Others may require an appointment.
Additional locations for blood testing may include:
Everything you eat and drink contains vitamins, proteins, and other nutrients that can cause the related levels in your blood to temporarily spike or drop.
Fasting for 8 to 12 hours helps ensure that blood test results are free from these variables, making your test results as accurate as possible.
Some common tests that may require fasting include:
Results may take anywhere from a few hours to a few days to become available. Here's an overview of how long some common tests may take:
Timing can depend on the specific lab where you get tested, and how many tests you get done at once. If you order multiple tests, you may not get the complete results until all of the tests are completed.
Sometimes a lab will only release results to your doctor, who reviews them and then releases them to you.
While every laboratory or test-providing company may structure their result reports differently, they all must include the same components as mandated by federal legislation.
Some of that may be administrative content, such as the name of the person who did the blood test, the date the test was done, and the name of the doctor who ordered the test.
When it comes to understanding the results, you can look for the following:
A nurse or technician usually performs a blood test at a laboratory or in a doctor's office. The procedure takes just a few minutes.
To perform a blood test, the nurse or technician:
The risks of routine blood tests are very low but can include:
Blood tests can offer a good snapshot of your overall health.
They're also a good way to catch illness or disease early, and to see how well your body responds to treatments for various conditions.
Many people get routine blood tests done at least once a year. Talk with your doctor to learn whether there are any other tests you may need to ensure your optimal health.
Blood Test Could Ease Diagnosis Of Kids' Inflammatory Conditions
Elevations in a single cytokine species were uniquely characteristic of Kawasaki disease in children versus other inflammatory disorders with similar presentations, researchers said, paving the way for a blood test to aid differential diagnosis.
High levels of one particular interleukin (IL) protein -- IL-17A -- were diagnostic for Kawasaki disease as opposed to other pediatric fever conditions, with astonishingly high accuracy: an area under the receiver operating characteristic curve (AUC) of 0.95, according to Pui Y. Lee, MD, PhD, of Boston Children's Hospital, and colleagues.
"Elevation of all three IL-17-family cytokines [including IL-17-C and -F] was observed in >50% of KD [Kawasaki disease] patients, including 19 of 20 with coronary artery aneurysms, but was rare in all other comparator groups," the group reported in Arthritis & Rheumatology.
"Our findings support further investigation of the IL-17 cytokine family as diagnostic markers for KD and as potential risk factors for [coronary artery aneurysm] development," Lee and colleagues added.
Kawasaki disease is a form of vasculitis in children affecting mid-sized vessels. It's been recognized for a half-century, yet its underlying pathology remain mysterious, with diagnoses based on what Lee's group called "ambiguous clinical manifestations" such as fever, rash, and limb edema. These symptoms are also seen in a host of other conditions, such as viral infections, certain toxin exposures, and multisystem inflammatory syndrome in children (MIS-C), which each require different treatments.
The researchers noted, too, that "up to one-third of cases with [aneurysms] do not fulfill the classic diagnostic criteria" for Kawasaki disease.They emphasized that diagnosing Kawasaki disease quickly is imperative because coronary artery deformities develop in up to 30% of cases if the condition is not treated successfully.
Consequently, Lee's group sought to identify blood-based biomarkers that could aid in the differential diagnosis of children's inflammatory diseases, using a technology called the proximity extension assay (PEA). This method is capable of quantifying multiple proteins simultaneously in a single sample as small as 1 μL, the researchers said.
Lee and colleagues first obtained blood samples from 104 children: 23 diagnosed with Kawasaki disease, 25 with MIS-C, 26 with other fever disorders, 46 with various juvenile rheumatologic disorders (including 13 with macrophage activation syndrome), and 30 healthy individuals. Samples were then analyzed via PEA for 42 different cytokine species including interleukins, chemokines, interferons, tumor necrosis factors, and others.
Potential diagnostic markers were then checked in a separate validation cohort consisting of 37 Kawasaki disease patients and 28 febrile controls.
IL-17 proteins (including subspecies C and F as well as A) performed the best, not only for discriminating Kawasaki disease from febrile conditions, but also against MIS-C.
"[E]levation of the IL-17 cytokine family is a hallmark of Kawasaki disease," Lee and colleagues concluded.
That their approach was generally correct was confirmed by findings in patients with rheumatologic musculoskeletal conditions such as systemic juvenile idiopathic arthritis (sJIA). Cytokine profiles that Lee's group derived matched those from previous studies: for example, IL-18 was elevated in sJIA with macrophage activation syndrome, while interferon-induced chemokine levels were increased in juvenile dermatomyositis.
However, the researchers cautioned that more research remains to be done. "Although we provide data from an independent validation cohort of KD and febrile controls, a key limitation of our study is that all samples were obtained from a single center. Additional validation with samples from multiple sites is needed to confirm the generalizability of these findings," they noted. Another limitation was that some children in the rheumatologic condition cohort were receiving immunosuppressants that likely affected their cytokine profiles.
"Future studies are also needed for longitudinal analysis, which will be helpful in characterizing how IL-17 levels correspond to treatment response," Lee and team wrote.
John Gever was Managing Editor from 2014 to 2021; he is now a regular contributor.
Disclosures
The study was funded through U.S. Government and nonprofit foundation grants.
Authors reported relationships with numerous pharmaceutical companies and other commercial entities.
Primary Source
Arthritis & Rheumatology
Source Reference: Brodeur KE, et al "Elevation of IL-17 cytokines distinguishes Kawasaki disease from other pediatric inflammatory disorders" Arthritis Rheumatol 2023; DOI: 10.1002/art.42680.
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Modifiable Risk Factors Found To Be Responsible For Half Of Cardiovascular Diseases
Scientists of the Global Cardiovascular Risk Consortium under the auspices of the Department of Cardiology at the University Heart & Vascular Center of the Medical Center Hamburg-Eppendorf (UKE) and the German Center for Cardiovascular Research (DZHK) have proven that the five classic cardiovascular risk factors—excess weight, high blood pressure, high cholesterol, smoking, and diabetes mellitus—are directly connected to more than half of all cardiovascular diseases worldwide. High blood pressure is the most significant factor for the occurrence of heart attacks and strokes.
The study's results were published August 26 in the New England Journal of Medicine and are based on the data from 1.5 million persons from 34 countries.
Cardiovascular diseases cause approximately a third of all deaths worldwide. They often develop silently over decades. Frequently without being recognized, the vascular walls change, giving rise to arteriosclerosis, in the wake of which coronary heart disease may occur, including complications such as heart attacks, acute cardiac death, or strokes.
"Our study clearly shows that over half of all heart attacks and strokes are avoidable by checking and treating the classic risk factors. These results are of the highest significance for strengthening prevention in this area. At the same time, approximately 45% of all cardiovascular cases cannot be explained with these risk factors; they should motivate us and the academic funders to further research efforts," says Professor Doctor Stefan Blankenberg, the medical director of the University Heart & Vascular Center at the UKE.
The Global Cardiovascular Risk Consortium assessed the individual-level data of 1.5 million persons who took part in 112 cohort studies and originate from the eight geographical regions North America, Latin America, Western Europe, Eastern Europe and Russia, North Africa and the Middle East, Sub-Saharan Africa, Asia and Australia. The objective of the study was to gain a better understanding of the global distribution, the significance of the individual risk factors and their effects on cardiovascular diseases, and overall mortality in order to derive targeted preventive measures.
"In principle, the five classic risk factors that we examined are modifiable, and thus responsive to preventive measures. So far, the proportion of preventable risk attributed to these five risk factors is still matter of debate," lead author and associate professor Dr. Christina Magnussen, Department of Cardiology at the University Heart & Vascular Center of the UKE, explains.
Regional differences in risk factorsThe study showed differences in the eight global regions regarding the frequency of the risk factors. The scientists saw the highest rates for overweight in Latin America, and the highest values for high blood pressure and high cholesterol in Europe. The risk factor smoking is particularly decisive in Latin America and Eastern Europe, diabetes mellitus in North Africa and in the Middle East.
All five risk factors combined (excess weight, high blood pressure, high cholesterol, smoking, and diabetes mellitus) amount to 57.2% of women's cardiovascular risk and to 52.6% of men's. Thus, a substantial share of cardiovascular risk remains unexplained. In comparison, the five risk factors merely account for about 20% of the risk to die (overall mortality).
Furthermore, the study also clearly shows a linear relation between high blood pressure, and high cholesterol, and the occurrence of cardiovascular diseases. The higher the values, the higher the likelihood of the occurrence of cardiovascular diseases. This result applies to all examined regions in the world. The scientists also identified a remarkable connection between cholesterol levels and overall mortality: Very low as well as high cholesterol levels increase overall mortality.
The significance of all risk factors decreases with age; e.G., high blood pressure is more damaging to a 40 year old than an 80 year old. The body mass index (BMI) is the only exception and remains equally significant at any age. "This raises the question to which extent the target values for treating cardiovascular risk factors for the most elderly should be identical with those for the middle to older age bracket," says Professor Blankenberg.
Study identifies extensive range of starting points for preventive measuresThe study provides an extensive dataset to avoid cardiovascular diseases or reduce their effects for at-risk persons, or patients with cardiovascular diseases, by improving their lifestyle and by lowering blood pressure or cholesterol.
"High systolic blood pressure accounts for the largest share of cardiovascular risk. We should place a particular focus on the therapy of patients with high blood pressure to avoid cardiovascular diseases as much as possible," says associate professor Dr. Magnussen.
More information: Global Effect of Modifiable Risk Factors on Cardiovascular Disease and Mortality, New England Journal of Medicine (2023). DOI: 10.1056/NEJMoa2206916
Provided by Universitätsklinikum Hamburg-Eppendorf
Citation: Modifiable risk factors found to be responsible for half of cardiovascular diseases (2023, August 28) retrieved 28 August 2023 from https://medicalxpress.Com/news/2023-08-factors-responsible-cardiovascular-diseases.Html
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