Red blood cells are the part of your blood that carry oxygen from your lungs to the rest of your body. They also help remove carbon dioxide, which your body doesn’t need.
Your body makes red blood cells in the bone marrow. They get their red color from a protein called hemoglobin. Hemoglobin grabs oxygen and helps deliver it to your muscles, brain and organs so they can work properly.
Abnormal red blood cells don’t look or work the way they should. They may be the wrong shape, size or color — or they may not live as long as they should. With any of these issues, the body can’t carry enough oxygen to organs and tissues.
Some common types of abnormal red blood cells include:
- Sickle-shaped cells (seen in sickle cell disease): These cells are stiff and crescent-shaped. They can block blood flow and break apart easily.
- Very small or pale cells (seen in iron-deficiency anemia): These cells don’t carry enough hemoglobin, so they carry less oxygen.
- Large, immature cells (seen in megaloblastic anemia): These cells are too big and not fully developed, so they don’t work well.
- Misshapen or fragile cells (seen in spherocytosis or thalassemia): These cells break down more quickly than normal ones.
Abnormal red blood cells often lead to anemia, which can cause fatigue, weakness or other health issues. Doctors use blood tests to look at the shape, size and number of red blood cells to help find out what’s wrong and how to treat it.
