Red blood cells supply oxygen to all of the tissues in the body. Also known as erythrocytes, these tiny transporters pick up the oxygen from the air we breathe in as they pass through the lungs. The hemoglobin in the red blood cells temporarily binds to oxygen molecules (02) that pass through the cell membrane. The red blood cells also carry waste products of cellular respiration (CO2) away from the tissues, where it is later released as we exhale.
Doctors test your red blood cell count (RBCs) to be sure your tissues are receiving a healthy amount of oxygen, which is vital to good overall health. The normal range for red blood cell count in men is 4.7 to 6.1 million cells per microliter, while for women the range is 4.2 to 5.4 million mcL.
A low blood cell count could manifest as several symptoms, including shortness of breath, dizziness, rapid heart rate, pale color to the skin, fatigue, or frequent headaches.
A high red blood cell count may also cause shortness of breath, fatigue, joint pain, itching, disruption of normal sleep patterns, and joint pain.
When preparing for a red blood cell test, be sure to alert your doctor to any medications you may be taking, including nutritional supplements or over-the-counter remedies.
A red blood cell count is usually performed at an office visit, where your doctor will use a syringe to draw blood from a vein in the inner elbow. The doctor will clean the area with an antiseptic pad, then wrap a rubber tube or elastic band around your upper arm. He or she will then pierce the vein with the needle of the syringe, and extract the appropriate amount of blood. The puncture wound will then be covered with a bandage.