What Are the 5 Main Blood Tests?

1. Complete blood count (CBC)

One of the most common blood tests. It frequently occurs as part of a regular checkup. Among other blood components, this test counts your red blood cells, white blood cells, and platelets. CBC is used to assess nutritional status, screen for diseases, and ascertain general health conditions. It can aid in the evaluation of signs such as weakness, exhaustion, and bruises and diagnosis of illnesses such as anemia, leukemia, malaria, and infection.

CBC includes:

• Total concentration amount of hemoglobin present in the blood (Hgb)
• Fraction of blood composed of red blood cells (Hct)
• Hemoglobin volume in each RBC (mean corpuscular volume [MCV])
• Weight of hemoglobin in each RBC (mean corpuscular hemoglobin [MCH])
• The proportion of hemoglobin in each RBC (mean corpuscular hemoglobin concentration [MCHC])
• Number of platelets, which are critical to the formation of the clot
• MCV, MCH, and MCHC values help diagnose various types of anemia

Normal ranges for a CBC

• Normal range Hgb:
  • Men: 13.0 to 17.0 g/dL
  • Women: 11.5 to 15.5 g/dL
• Hematocrit normal range:
  • Men: 40 to 55 percent
  • Women: 36 to 48 percent
• Platelet count normal range:
  • Adult: 150,000 to 400,000/mL
• White blood cell normal range:
  • Adult: 5,000 to 10,000/mL

2. Basic metabolic panel (BMP)

Evaluates blood urea nitrogen, glucose, sodium, potassium, calcium, chloride, carbon dioxide, and creatinine, which can help determine renal function, electrolyte balance, and fluid balance. BMP assists your doctor in making diagnoses, aiding in normal health screenings, or monitoring the effects of drugs you are taking, such as those for high blood pressure. Before this test, you might need to fast for up to 12 hours.

BMP includes:

• Calcium: Normal range is 8.5 to 10.2 mg/dL (2.13 to 2.55 mmol/L). Your cells require calcium to function properly. Additionally, calcium aids in regular blood clotting.
• Carbon dioxide: Normal range is 23 to 29 mmol/L. This can serve as a measure of the health of your kidneys and lungs.
• Chloride: Normal range is 96 to 106 mmol/L. This is a measurement of the fluid balance in your body.
• Creatinine: Normal range is 0.8 to 1.2 mg/dL (70.72 to 106.08 µmol/L). Your kidneys produce this naturally, and the amount you have can tell you how well they're working.
• Glucose: Normal range is 64 to 100 mg/dL (3.55 to 5.55 mmol/L). Blood sugar, or glucose, is an important source of energy for your body, but having too much or too little of it can cause problems.
• Potassium: Normal range is 3.7 to 5.2 mEq/L (3.7 to 5.2 mmol/L). The health of cells is greatly influenced by this mineral.
• Sodium: Normal range is 136 to 144 mEq/L (136 to 144 mmol/L). This mineral is essential for ensuring that blood, tissues, and cells have adequate water to function properly.
• Blood urea nitrogen: Normal range is 6 to 20 mg/dL (2.14 to 7.14 mmol/L). This is another byproduct of renal function that demonstrates the health of your kidneys.

3. Blood enzyme test

This test may be used to look for heart attacks. Chemicals called enzymes to aid in regulating chemical reactions in the body. Blood enzyme testing come in a variety of forms. Tests for heart attacks include those for troponin and creatine kinase (CK). When a person has muscle damage, particularly damage to the heart muscle, blood levels of troponin increase. In addition, when the heart (cardiac) muscle is damaged, an enzyme called CK-MB is released into the blood. High blood levels of CK-MB can indicate that you've had a heart attack.

According to the American Board of Internal Medicine, reference ranges for the troponin test are expressed in nanograms per milliliter (ng/mL) as follows:

• Troponin I: 0 to 0.04 ng/mL
• Troponin T: 0 to 0.01 ng/mL

The range of acceptable reference values for serum CK-MB is three to five percent (percentage of total CK) or 5 to 25 IU/L.

4. Lipoprotein panel

Also known as a lipid panel or lipid profile and assesses your blood's low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride concentrations. Most people must fast for 9 to 12 hours before a lipoprotein panel. Increased or lower-than-normal levels of triglycerides and cholesterol may indicate a high risk of coronary heart disease.

An analysis of your lipoproteins reveals:

• Total cholesterol
• LDL (bad) cholesterol, the primary cause of artery blockages and cholesterol accumulation
• HDL (good) cholesterol, which aids in reducing artery blockages caused by cholesterol
• Triglycerides are a form of fat found in your blood

Normal ranges of lipid profile

• Total cholesterol
  • Normal: Lower than 200 mg/dL
  • Borderline high: 200 to 239 mg/dL
  • High: At or higher than 240 mg/dL
• LDL cholesterol
  • Optimal: Lower than 100 mg/dL (This is the goal for people with diabetes or heart disease.)
  • Near-optimal: 100 to 129 mg/dL
  • Borderline high: 130 to 159 mg/dL
  • High: 160 to 189 mg/dL
  • Very high: 190 mg/dL and higher
• HDL cholesterol
  • The level must be higher than 40 mg/dL. This sort of fat is beneficial for you because it reduces your risk of heart disease. Lower risk is indicated by a higher number. 
  • Protection for heart disease is thought to be attained at a level of 60 mg/dL or above.
• Triglycerides
  • Normal: Lower than 150 mg/dL
  • Borderline high: 150 to 199 mg/dL
  • High: 200 to 499 mg/dL
  • Very high: Higher than 500 mg/dL

5. Blood clotting tests

Look for proteins in your blood that affect how your blood clots. Levels that are abnormally high or low could indicate that you're in danger of bleeding or getting blood clots in your blood vessels. Blood clotting tests are also used to track the health of people who take medications to reduce their risk of blood clots. Two examples of such medications are heparin and warfarin.

Doctors frequently order blood clotting tests (coagulation tests) such as:

• D-dimer test 
  • Detects D-dimer in the blood (a protein fragment formed in the body when a blood clot dissolves) 
  • A normal D-dimer is considered <0.50
  • A positive D-dimer is >0.50 
  • As D-dimer is a screening test, a positive D-dimer is a positive screen. There is no critical level for a D-dimer.
• Prothrombin time (PT)/INR test 
  • PT test determines how long it takes for a blood clot to form in a blood sample. An INR is a calculation based on PT test results.
  • PT: 11 to 13.5 seconds
  • INR: 0.8 to 1.1
• Activated partial thromboplastin time test 
  • PT test determines how long it takes for a blood clot to form in a blood sample. An INR is a calculation based on PT test results.
  • A normal range is between 21 and 35 seconds.

The following steps are followed by a doctor or a nurse while withdrawing blood samples for blood tests:

• For the test, you can either sit or lie down.
• The ideal vein is selected by a doctor, nurse, or phlebotomist (someone skilled in drawing blood). Usually, this comes from your hand or arm. Tell them if you have a needle phobia, get sick at the sight of blood, or have a latex or plaster allergy.
• Above the spot where they collect the sample, they tighten a tourniquet (band) around your arm. Finding a vein can require you to tighten your fist.
• A little needle is inserted into your vein after your skin has been cleaned. Next, they squeeze a little blood out of the needle using a little vial or syringe. A few tiny bottles might be filled.
• When they've collected all the samples, they let go of the armband that's been fastened to it. The needle is then removed, and the affected area is compressed for a short period using a cotton ball or a piece of gauze. As a result, bleeding and bruising are reduced.

Test results differ depending on the equipment and methods used. As a result, standard normal results will differ from each lab.

Phlebotomy, or drawing blood, is a secure procedure.

Possibilities of risk include:

• Bleeding and bruising, which are avoided by pressing firmly after the needle is removed 
• Pain, which is typically minor and might continue for several minutes
• Ask your nurse, doctor, or phlebotomist to avoid taking a blood sample from an arm that is swollen or in danger of edema (swelling)
• If you ever feel dizzy, alert the person taking your blood
• Infection (this is relatively uncommon)