Blood tests can help a doctor diagnose a variety of health conditions, including infections, anemia, high cholesterol, vitamin deficiencies, organ failure, HIV, cancer, and diabetes.
Doctors use blood tests to analyze substances like proteins, cells, or chemicals in your blood.
This can give them a picture of your overall health and help them diagnose different diseases, monitor chronic conditions, assess your organ function, and determine your immune system strength.
Regular blood testing is one of the most important ways to keep track of your overall physical well-being. We’ve partnered with Lifeforce to bring you this overview article on blood tests.
Let’s take a closer look at some common blood tests.
1. Complete blood count
A routine complete blood count (CBC) checks for levels of different components in your blood.
Here’s the
| Component | Normal range |
| red blood cells (cells responsible for carrying oxygen throughout the body) | male: 4.5–6.1 × 106/ microleter (μL); female: 4.0–5.4 × 106/μL |
| white blood cells (immune system cells in the blood) | male: 4.0–10.8 × 103/μL female: 4.0–10.8 × 103/μL |
| platelets (the substances that control the clotting of the blood) | male: 150–400 × 103/μL female: 150–400 × 103/μL |
| hemoglobin (protein within the red blood cells that carries oxygen to organs and tissues and carbon dioxide back to the lungs) | male: 13.0–17.0 grams/deciliter (g/dL); female: 12.0–16.0 g/dL |
| hematocrit (percentage of blood made of red blood cells) | male: 40–52%; female: 37–47% |
Based on your results, your doctor will order follow-up tests to confirm abnormal levels and a possible diagnosis.
2. Basic metabolic panel
A basic metabolic panel usually checks for levels of eight compounds in the blood:
- calcium
- glucose
- sodium
- potassium
- bicarbonate
- chloride
- blood urea nitrogen
- creatinine
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.
Your doctor will perform follow-up tests to confirm a diagnosis.
The Lifeforce Diagnostic is an at-home blood test designed to gather data on 40+ biomarkers that impact your health and longevity, including your metabolic condition, hormone health, and key risk factors for disease. Your diagnostic includes an at-home blood draw from an experienced phlebotomist, a telehealth consultation with a Lifeforce clinician, and a personalized plan that consists of expert insights, lifestyle improvements, nutraceuticals, and hormone and peptide therapies.
3. Comprehensive metabolic panel
A comprehensive metabolic panel (CMP) includes all the measurements of a BMP as well as additional proteins and substances related to liver function, such as:
- albumin, this is the main protein in your blood. It’s made in your liver.
- total protein, this is the total amount of protein in your blood. It includes albumin and globulins, which are mainly made in your liver.
- alkaline phosphatase (ALP), an enzyme mostly found in the bones and liver that’s involved in several bodily processes
- alanine aminotransferase (ALT), an enzyme found in the liver
- aspartate aminotransferase (AST), an enzyme found in the liver and other tissues within the body
- bilirubin, which is waste resulting from the breakdown of red blood cells that the liver filters out
4. Lipid panel
This test checks levels of
- high-density lipoprotein (HDL), or “good†cholesterol
- low-density lipoprotein (LDL), or “bad†cholesterol
You may need to fast for at least 8 hours before this test.
HDL cholesterol levels of 60 milligrams per deciliter (mg/dL) or above are 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.
Typical levels can also vary by age. A lipid panel also checks for triglycerides.
5. Thyroid panel
A thyroid panel, or thyroid function test, checks how well your thyroid is producing and reacting to certain hormones, such as:
- Triiodothyronine (T3): Along with T4, this regulates your heart rate and body temperature.
- Thyroxine (T4): Along with T3, this regulates your metabolism and how you grow.
- Thyroid-stimulating hormone (TSH): This helps regulate the levels of hormones your thyroid releases.
Your thyroid is a tiny gland in your neck. It helps regulate bodily functions like your mood, energy level, and overall metabolism.
Abnormal levels of these hormones can indicate underactive thyroid (hypothyroidism) or overactive thyroid (hyperthyroidism).
6. Cardiac biomarkers
Common markers include:
- High-sensitivity cardiac troponin (hs-cTn):This is a heart protein that is a marker of heart injury.
- B-type natriuretic peptide (BNP) and N-terminal pro b-type natriuretic peptide (NT-proBNP): BNP is a hormone that is released when the heart muscle is stretched, generally caused by fluid overload in congestive heart failure.
- Creatine kinase (CK): This enzyme is primarily located in the brain, heart, and skeletal muscle. When muscle damage happens, CK seeps into the blood in growing amounts.
- Creatine kinase-MB (CK-MB): These enzymes are found in your heart. They often increase in your blood after a heart attack or other heart injury.
7. Sexually transmitted infection tests
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.
Blood tests aren’t always accurate right after contracting an infection. It can take three to six months after exposure to get a positive blood test. This is why it is important to repeat testing.
8. Coagulation panel
Coagulation 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 stop bleeding after a cut or wound. However, 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.
9. DHEA-sulfate serum test
The 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 females, high levels can cause typically male traits, like excess body hair, to develop, so low levels are normal.
10. C-reactive protein test
C-reactive protein (CRP) is made by your liver when tissues in your body are inflamed.
The
- <0.3 mg/dL: normal
- 0.3 to 1.0 mg/dL: minor elevation can be associated with a person’s sex, high body mass index (BMI), or with conditions like depression or insomnia
- 1.0 to 10.0 mg/dL: moderate elevation usually caused by systemic inflammation, such as from an autoimmune disease, bronchitis, heart attack, or cancer
- >10.0 mg/dL: marked elevation typically caused by a serious bacterial or viral infection, major trauma, or systemic vasculitis
- >50.0 mg/dL: severe elevation usually caused by an acute bacterial infection
Smoking and gingivitis may also be linked with heart disease. More and more evidence suggests a link between oral health and overall inflammation.
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.