A Guide to Common Blood Tests

Page content

Blood tests are a simple way for doctors to check for certain diseases and conditions, such as HIV, diabetes and cancer. Plus, they allow doctors to see how well your organs are working and how effective treatments are for you. A routine blood test can let your doctor monitor your overall health by examining your blood regularly.

An Overview to Blood Tests

Most common blood tests don’t require any special preparations, but for some you may need to fast for 8 to 12 hours before having your blood drawn. After a small sample of blood is collected, laboratory technicians will analyze its contents. Often, whole blood counts are taken or blood cells may be separated from the plasma. The cells and plasma both contain vital information used to diagnose and treat medical conditions. Although blood tests can tell a doctor a lot about your body, further testing is often needed to confirm a diagnosis.

Routine Blood Tests

Routine blood tests are usually conducted annually to monitor overall health. A routine blood test checks the number of red blood cells and how much hemoglobin is in the blood. Often, a mean corpuscular volume (MCV) will be conducted at the same time to measure the size of the red blood cells. This test will determine if a person suffers from anemia due to low hemoglobin levels. The size of the red blood cells will determine the type of anemia. Sleeping sickness, malaria and blood poisoning can be diagnosed with this test as well.

White blood cells are counted during routine blood tests, called a differential WBC count. This test can diagnose bacterial infections, leukemia, cancer and malaria if WBC levels are elevated. Low WBC levels are a sign that an autoimmune disorder may be present. Monitoring WBC levels allows doctors to monitor diseases as well.

Platelets are also checked to determine how well the blood clots. Low numbers may indicate a bleeding disorder, autoimmune disease, viral infections or leukemia. However, low levels can also be the result of medications and chemotherapy. High platelet levels can indicate a person is susceptible to blood clots.

Blood Tests for Organ Functions

During Basic Health Screenings, a Complete Metabolic Profile (CMP 12) and Complete Blood Count (CBC) are taken. These tests allow doctors to see how the major organs in the body are functioning, such as the heart, liver, kidneys and muscles. Elevated or low levels can indicate a problem.

Specific Blood Tests

Blood tests are also used to diagnoses specific conditions, such as high or low cholesterol, heart conditions and cancers. Rare disorders can be identified through blood tests as well. These blood tests are used when a suspected underlying condition is present. Detailed testing is also conducted during pregnancy. Pregnancy can also be detected through the use of a blood test, as well as certain conditions associated with pregnancy, such as gestational diabetes.

NB: The content of this article is for information purposes only and is not intended to replace sound medical advice and opinion.


“Blood Tests” https://www.netdoctor.co.uk/health_advice/examinations/bloodsamples.htm

“What are Blood Tests” https://www.nhlbi.nih.gov/health/health-topics/topics/bdt/