October 5, 2023 Author : Ana Sofia Corredoura Sedimentation rate or erythrocyte (red blood cell) sedimentation rate is a test that indicates whether inflammation is present in the body . It is not a specific test as it does not identify the cause of the inflammation. It is done on a blood sample. It is part of the group of diagnostic tests currently known as blood tests. It is requested quite frequently, even in routine analyses. It may be an additional test to assess the inflammatory response throughout a disease process. It does not require prior fasting, but it is generally done together with other blood tests, some of which require fasting. How sedimentation rate is performed A blood sample is placed in a specific, tall and narrow tube, and the rate at which red blood cells settle to the bottom is assessed . When blood is placed in a tube or other container, there is a tendency for red blood cells to gradually settle to the bottom due to gravity because the cells have a higher density than plasma (the liquid component of blood). When there is inflammation, red blood cells tend to clump together and they clump together more the more severe the inflammation. The clusters of cells are denser and heavier than individual cells and therefore settle to the bottom more quickly. The sedimentation rate result is presented in millimeters per hour (mm/h), and its value reflects the distance that the red blood cells traveled towards the bottom of the tube in one hour. The results As with any medical test, the sedimentation rate results must be interpreted by a doctor , together with the data from the physical exam he carried out on the patient and the results of other tests already carried out or that may be necessary. If a sedimentation rate result is outside normal values and depending on each person's context, the doctor will decide on the need to carry out additional tests. As with results of other blood tests, sedimentation rate values may vary somewhat and be outside the reference values without any disease being present: Sedimentation rate increases with age and is slightly higher in women; Anemia, pregnancy, kidney disease, obesity or smoking can increase the sedimentation rate; Some changes in red blood cells, white blood cells, heart failure, cachexia, physical activity, or alcohol consumption can reduce the sedimentation rate; There may be variations from laboratory to laboratory and, therefore, whenever possible, it is advantageous for the same person to use the same laboratory to carry out their blood tests. Given the high number of factors that can affect the sedimentation rate, its use is limited in diagnosing active disease or in therapeutic decisions . The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
