Sedimentation rate blood test
The sedimentation rate blood test which is also known as Erythrocyte Sedimentation Rate Test (ESR) or Westergren test is used to measure the rate at which red blood cells of a blood sample settle in a tube. The ESR is a non-specific inflammation measure and is used by healthcare providers to diagnose conditions such as autoimmune disorders, infection, cancer, and pregnancy. Not only does this test help in diagnosing these conditions, but it can also be used to monitor the effectiveness of their treatment.
The ESR blood measures the speed at which the red blood cells (RBCs) fall to the bottom of a tube of blood. Inflammation in your body can cause clumping of cells and these clumps are denser than individual cells. This is why they settle to the bottom more quickly. The sedimentation rate blood test measures the distance that RBCs fall in one hour in a test tube. The faster these red blood cells move to the bottom, the greater the inflammatory response of your immune system.
When there is an acute infection or chronic inflammation in the body, it may result in excess proteins in your RBCc, making them settle quickly. The faster and further they sink toward the bottom of a test tube, the more chances there are of inflammation.
When do you need the ESR test?
You might need the ESR test if you are experiencing any symptoms of inflammatory conditions such as arthritis or inflammatory bowel disease (IBD). These symptoms are:
- Joint stiffness or pain that lasts for more than 30 minutes in the morning
- Unintentional weight loss
- Headaches, especially when it is accompanied by pain in the temples and vision changes
- Digestive symptoms such as diarrhea, blood in the stool, unusual abdominal pain or fever
- Pain in the neck, shoulders, or pelvis
Common conditions detected with a sedimentation rate blood test
- Infection is one of the most common conditions that can be detected using a sedimentation rate blood test. If you are experiencing symptoms such as swollen lymph nodes, fever or a rash, your healthcare provider may prescribe this test to help detect the infection.
- Lupus is another common condition that the Erythrocyte Sedimentation Rate Test can detect. It is an autoimmune disease that results in inflammation and pain in various parts of the body. This test can help your doctor detect if you have lupus and can help in ruling out other possible causes of the symptoms you are experiencing.
- Cancer is also one of the ailments that can be screened with a sedimentation rate blood test. Your doctor may prescribe this test to see if there is an underlying cancerous tumor causing any unusual symptoms.
How is the sedimentation rate blood test done?
This test is done on a venous blood sample, drawn from a vein in the arm. A path lab technician will draw the blood sample from a vein in your arm and then place the blood sample in a special tube. This tube is then placed in a machine that measures the speed at which red blood cells fall to the tube’s bottom. A sedimentation rate blood test is done on an empty stomach (fasting) which means that you should not eat or drink anything for 8 hours before this test. In case you are taking any medications, your doctor may ask you to stop taking them temporarily before the ESR test.
Since a sed rate test cannot conclusively detect the problem causing inflammation, it is usually done along with other blood tests, such as the C-reactive protein (CRP) test. The sed rate is measured in millimeters per hour (mm/hr). The normal range for this test is 0 to 22 mm/hr (men) and 0 to 29 mm/hr (women). In conditions such as rheumatoid arthritis, lupus, and temporal arteritis, ESR can be elevated. It can also be high as a reaction to some medications such as aspirin.
Risks and side effects associated with the ESR blood test
It is important to know the risks and side effects associated with any kind of blood.
- One of the most common risks associated with an ESR blood test is that of a false positive. This may happen if you have an infection or another condition that may cause your sed rate to increase but does not cause any inflammatory activity in your body. If this occurs, you may have to undergo additional testing or may be prescribed a treatment that you do not require.
- This test can also cause an increased heart rate or other adverse side effects in some people. You should also be aware of any symptoms such as chest pain, shortness of breath, or swelling in the ankles or feet after the test. You must contact your doctor immediately in case you experience any of these side effects.
The sedimentation rate blood test is a simple and non-invasive test that measures inflammation in the body. It can be used for diagnosing conditions such as rheumatoid arthritis, lupus, and polymyalgia rheumatica. You can book this test even without a doctor’s note.