what is rbc in blood test

An RBC count, or red blood cell count, is a blood test that measures the number of red blood cells (RBCs) in the blood. Red blood cells contain hemoglobin, a protein that carries oxygen throughout the body. The test is usually part of a complete blood count (CBC) and is used to diagnose various conditions, including anemia and other disorders affecting red blood cells. Normal RBC ranges are 4.7 to 6.1 million cells per microliter for males and 4.2 to 5.4 million cells per microliter for females. Abnormal results can indicate conditions such as anemia, vitamin deficiencies, internal bleeding, kidney disease, or high altitude living. A high RBC count could also be caused by factors such as smoking, dehydration, or certain health conditions like congenital heart disease or pulmonary fibrosis.