I had my annual doctor’s check up recently, and they requested that I get a blood draw. The lady that took my blood used multiple bottles (seems like to me I got a full work up) and I was wondering what those bottles meant. How does isolating different parts of my blood check for liver and kidney function, when the doctors will be looking at my blood – and not the actual organs? How do doctors diagnose diseases/conditions based on my blood, and are there certain conditions that are more prevalent in mixed racial communities? Being mixed racial, I’d certainly like to know.

So the fix? I watched a YouTube video! Here’s the link if you all want to watch it too: Blood Bottles Guide by Geeky Medics

But I’m just going to sum up what they said here.

Purple Blood Bottles: Hematology Tests

Full Blood Count (FBC) or Complete Blood Count (CBC) – the most common Hematology Test. Tests for:

• Hemoglobin (Hgb) – a protein, holds oxygen in your blood
• Platelets (PLT) – help with blood clotting
• White Cell Count (WCC) – help your immune system protect your body from disease/illness

HbA1C: Diabetic Blood Sugar Control – another common Hematology Test

• reports a patient’s average level of blood sugar over the previous 2-3 months

So those are some words on a page…but what do they actually mean? Turns out a Full Blood Count is a test that counts the cells that make up your blood. This includes RBCs (red blood cells), white blood cells, and platelets. You’re not required to fast before having this test, and it can tell your doctor a lot of basic medical information (for example, to help with diagnosis of anemia (fewer functioning RBCs than normal) or watch how your body may be responding to treatments such as chemotherapy and/or radiation). Take a look at the full article here.

Yellow/Gold – Biochemistry Test

Urea & Electrolytes is the most common Biochemistry Test. It provides information on renal function, including excretion (expelling waste) and homoeostasis in kidneys (the body’s tendency to look for equilibrium when faced with external changes). It tests for levels of:

• Sodium (Na) – electrolyte that helps maintain water balance in/around your cells
• Potassium (K) – necessary for electrolyte and fluid balance, needed for the function of all living cells
• Urea – the main component in urine, a waste product
• Creatinine – waste product, removed from the body by the kidneys to be expelled from the body via urine

Thyroid Function Tests (TFT) – another Biochemistry Test

• A test that reports the levels of thyroid hormone in your body
• T4 and TSH tests are the most common of these tests, and are usually ordered together
• A high level of T4 indicates an overactive thyroid (hyperthyroidism)
• TSH measures how much thyroid-stimulating hormone is in your blood

Blue – Hematology Tests to Assess Blood Clotting Function

Coagulation Screen: measures how long it takes for your body to clot

• Prothrombin Time Test (PTT) – a protein your liver produces, helps your blood clot. The average time range for blood to clot is 60-70 seconds. A higher number means your blood needs more time to clot, and a lower one means your blood clots more quickly than average. Fast clotting can be caused by supplements containing Vitamin K, and medications that contain estrogen (eg. birth control pills, hormone replacement therapy). Slow clotting can be caused by Vitamin K deficiency, liver problems, and blood thinning medications.
• Activated Partial Thromboplastin Time (APTT) – similar to the PTT, except in this test doctors will add a substance to your blood to increase clotting time. An average value is anywhere from 30-40 seconds.
• Fibrinogen – a protein that improves clotting function and reduces blood loss

D-Dimer Test: helps doctors figure out whether that patient has a significant blood clot or not

• D-Dimer is a leftover substance from the blood clotting process (part of a protein)
• If you have high levels of D-Dimer, you might have a major blood clot like DVT (deep vein thrombosis)
• DVT is a clot located deep in your of your veins, usually found in your legs
• The D-Dimer test can also help with diagnosis of a PE (pulmonary embolism), which is a blood clot that has traveled to your lungs
• D-Dimer is usually used in patients who are less likely to have blood clots to help completely rule them out

Grey: 2 Very Specific Biochemistry Tests

Blood Glucose: Measures the glucose levels in your blood, to determine whether they’re in a healthy range (helpful in diagnosing diabetes or monitoring diabetes)

• Fasting Glucose – a blood sample will be procured after fasting overnight. Results of less than 100 mg/dl is normal, 100-125 mg/dl prediabetic, and 125+ mg/dl diabetic (if found to be so on 2 separate tests).
• Random Glucose – a blood sample will be taken at a random time. It doesn’t matter when you ate last; a result of 200 milligrams per deciliter indicates diabetes

Lactate: Measurement of lactic acid in your blood, an acid made in RBCs and muscle cells. It’s a product of your body turning food into energy.

• If your lactic acid level returns normal, your cells are making enough oxygen and you don’t have lactic acidosis
• If it’s high, you most likely have a condition that makes it hard for you to breath in enough oxygen
• Take a look at this article to understand more about the concerns of a higher lactic acid level

Pink: Bottle sent to Blood Transfusion Lab

Group & Save:

• Gives your doctor a full analysis of your blood group

Crossmatch:

• Requests blood from the lab for the patient

Here’s some bonus information – on how to read your blood type results. Human blood is categorized by antigens on the surface of RBCs. The most significant antigens in blood typing are blood group antigens (ABO) and the Rh antigen (present = positive or absent = negative).