Blood Test

Blood Test

A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick. Blood tests are used to determine physiological and biochemical states, such as disease, mineral content, drug effectiveness, and organ function. They are one of the most common types of medical tests.

Types of Blood Tests

Blood tests can be categorized into several types based on their purpose and the components they analyze:

Complete Blood Count (CBC)

The Complete Blood Count (CBC) is a common blood test that evaluates overall health and detects a variety of disorders, including anemia, infection, and many other diseases. It measures several components and features of your blood, including:

• Red blood cells, which carry oxygen
• White blood cells, which fight infection
• Hemoglobin, the oxygen-carrying protein in red blood cells
• Hematocrit, the proportion of red blood cells to the fluid component, or plasma, in your blood
• Platelets, which help with blood clotting

Basic Metabolic Panel (BMP)

The Basic Metabolic Panel (BMP) is a group of tests that measures different chemicals in the blood. It includes tests for:

• Glucose, a type of sugar and your body's main source of energy
• Calcium, which is essential for the proper functioning of muscles, nerves, and the heart
• Electrolytes, such as sodium, potassium, bicarbonate, and chloride, which help regulate your body's fluid levels and acid-base balance
• Blood urea nitrogen (BUN) and creatinine, which are waste products filtered out of the blood by the kidneys

Lipid Panel

A Lipid Panel is a blood test that measures lipids—fats and fatty substances used as a source of energy by your body. It includes:

• Total cholesterol
• Low-density lipoprotein (LDL) cholesterol, often called "bad" cholesterol
• High-density lipoprotein (HDL) cholesterol, often called "good" cholesterol
• Triglycerides, another type of fat in the blood

Liver Function Tests

Liver Function Tests are blood tests that help diagnose and monitor liver disease or damage. They measure the levels of certain enzymes and proteins in your blood, including:

• Alanine transaminase (ALT)
• Aspartate transaminase (AST)
• Alkaline phosphatase (ALP)
• Bilirubin

Purpose of Blood Tests

Blood tests are used for a variety of reasons, including:

• To assess your general state of health
• To confirm the presence of a bacterial or viral infection
• To see how well certain organs, such as the liver and kidneys, are functioning
• To screen for certain genetic conditions
• To monitor chronic conditions, such as diabetes or high cholesterol

Procedure

The procedure for a blood test typically involves the following steps: 1. A healthcare professional will clean the area where the blood will be drawn. 2. A tourniquet is applied to the upper arm to fill the veins with blood. 3. A needle is inserted into a vein, usually in the arm, to draw blood. 4. The blood is collected into one or more vials or syringes. 5. The needle is removed, and the puncture site is covered to stop any bleeding.

Risks

Blood tests are generally safe, but they can cause some discomfort and minor side effects, such as:

• Bruising or bleeding at the puncture site
• Lightheadedness or fainting
• Infection at the puncture site (rare)

Also see

• Urinalysis
• Biopsy
• Imaging tests
• Electrocardiogram