What is Blood Chemistry?

serology.
A diagram showing different types of white blood cells.
Red blood cells.
Routine bloodwork is often done to check a patient's blood chemistry.
Article Details
  • Written By: Mary McMahon
  • Edited By: O. Wallace
  • Last Modified Date: 06 August 2014
  • Copyright Protected:
    2003-2014
    Conjecture Corporation
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Blood chemistry is the chemical composition of the blood. The levels of various substances in the blood can provide clues to a patient's condition, ranging from the presence of a liver disorder to a pregnancy. Routine bloodwork to check blood chemistry is often a part of a diagnostic workup, with the blood being analyzed to check for specific elements which could contribute clues to the diagnosis. Doctors rely on information about normal ranges of things like proteins and lipids to read the blood analysis.

A wide variety of things can be examined in a blood chemistry test. The basic composition of the blood in the form of numbers of white blood cells, red blood cells, and platelets is usually a routine part of the test. In the hematocrit reading, the technician doing the analysis looks at the percentage of red blood cells in the blood. Technicians also look at the amount of hemoglobin, the mean corpuscular volume, meaning the size of red blood cells, and the mean corpuscular hemoglobin, the average weight of the hemoglobin in a red blood cell.

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Blood tests can also look for specific enzymes, such as a family of enzymes which indicate the level of liver function. Levels of alkaline phosphatase, serum Glutamic-Pyruvic Transaminase (sGPT), and serum Glutamic-Oxaloacetic Transaminase (sGOT) can reveal information about how well the liver is functioning. Presence of electrolytes like sodium, potassium, chloride, and calcium can also be measured in a blood chemistry analysis, along with levels of proteins and lipids in the blood.

Specific tests can search for nitrogen elements including Blood Urea Nitrogren (BUN), uric acid, and creatinine, along with thyroid hormones which can be used to assess the level of thyroid function. In a glucose fasting test, the patient fasts for a set period of time before being tested for glucose to look for signs of diabetes. The analysis of any blood chemistry test also usually includes a discussion of the ratios of the various substances in the blood, along with information about normal ratio ranges which can be used to evaluate the results.

Everyone's blood is slightly different, and sometimes people have readings which fall outside the normal range without being a cause for concern. Doctors have to evaluate these cases on an individual basis to determine how a blood chemistry result should be addressed. Blood chemistry is usually one of the key steps in a differential diagnosis, in which a doctor or medical team explores all of the potential causes for a patient's condition and uses medical testing to rule out causes in order to arrive at a diagnosis.

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Discuss this Article

turquoise
Post 3

@simrin-- There are numerous test that measure levels of different elements in the blood. The cbc blood test is one of the most common but it doesn't measure iron levels. The cbc measures red and white blood cell count and hemoglobin among other things. For iron count however, the doctors had probably used a ferritin test for your sister. The blood chemistry lab must have found her iron levels to be less than 11 nanograms to declare her as iron deficient.

SteamLouis
Post 2

I remember when my sister was young, she was always tired and often fainted. The doctors had found that she had iron deficiency. I'm trying to recollect the name of the test, does the cbc blood test measure iron?

ysmina
Post 1

My mom gets a fasting blood test regularly to make sure that her type 2 diabetes is in control. The blood chemistry results show her hemoglobin A1c levels which is the average of her blood sugar levels of the past 3 months. The level is said to be normal if it is between 5 and 6 and dangerous if it is above 6. Many type 2 diabetes patients are unaware of their situation because they don't request for a glucose tolerance test, rather than just a regular blood sugar count. That's how my mom found out as well and now she is taking medication and her sugar levels are back to normal. If you are going to get your blood chemistry checked, make sure to ask for a glucose tolerance test if you have history of type 2 diabetes in your family. If you are a type 2 diabetes patient, then don't forget to ask for your hemoglobin A1c levels every 3 months.

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