What are Blood Tests?
Blood tests are laboratory analyses of a blood sample that help diagnose, monitor, and evaluate various health conditions. They provide valuable information about your overall health, organ function, and the presence of diseases or deficiencies.
What are the Common Types of Blood Tests?
Some of the common types of blood tests include:
- Complete Blood Count (CBC): Measures red and white blood cells, platelets, haemoglobin, and haematocrit to detect infections, anaemia, and blood disorders.
- Basic Metabolic Panel (BMP) & Comprehensive Metabolic Panel (CMP): Assesses kidney function, blood sugar, electrolytes, and liver function.
- Lipid Panel: Measures cholesterol levels (LDL, HDL, total cholesterol, and triglycerides) to assess heart disease risk.
- Liver Function Tests (LFTs): Evaluates liver health by measuring enzymes like ALT, AST, and bilirubin.
- Kidney Function Tests: Measures creatinine and blood urea nitrogen (BUN) to assess kidney performance.
- Thyroid Function Tests: Checks levels of TSH, T3, and T4 to evaluate thyroid health.
- Blood Sugar Tests (Glucose, HbA1c): Diagnoses and monitors diabetes.
- Vitamin and Mineral Tests: Checks for deficiencies in iron, vitamin D, B12, calcium, and magnesium.
- Infectious Disease Tests: Detects infections like HIV, hepatitis, and syphilis.
- Coagulation Tests (PT, INR, aPTT): Assesses blood clotting ability.
When Do You Need a Blood Test?
You may need a blood test for various reasons, depending on your health status, symptoms, or medical conditions. Some common situations when a blood test is necessary include:
- Routine Checkups: Annual health screenings and monitoring chronic conditions like diabetes, high cholesterol, or thyroid disorders.
- Diagnosing Symptoms: Investigating fatigue, fever, weight changes, or unexplained symptoms.
- Monitoring Medications: Checking the effects of blood thinners, diabetes meds, or cholesterol treatments.
- Disease Screening: Assessing risk for heart disease, diabetes, infections, or organ dysfunction.
- Preoperative Testing: Ensuring safety before surgery.
- Hormonal & Pregnancy Testing: Checking fertility, thyroid function, or pregnancy status.
What Happens During a Blood Test?
During a blood test, a healthcare professional follows these steps:
- You may be asked to fast (avoid food and drink) for certain tests.
- A tourniquet (elastic band) is placed around your upper arm to make veins more visible.
- The skin is cleaned with an antiseptic to prevent infection.
- A needle is inserted into a vein (usually in the arm) to draw blood into a vial.
- Once enough blood is collected, the needle is removed, and pressure is applied to the site.
- A bandage is placed over the puncture site.
Aftercare and Results
After a blood test, a bandage is placed over the puncture site, and you may experience mild bruising or soreness, which usually fades quickly. It is advised to avoid heavy lifting or strenuous activity with that arm for a few hours. Depending on the type of test, results can take anywhere from a few hours to several days. Once available, your doctor will review them and discuss any findings with you. If results are normal, no further action may be needed, but if abnormalities are detected, your doctor may recommend follow-up tests, lifestyle changes, or treatment options.