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"I have a smaller diameter than normal for red blood cells, is something wrong?"

ZocdocAnswersI have a smaller diameter than normal for red blood cells, is something wrong?


my iron levels are fine and doctor recommended me the SPE test. i was what could cause this if my iron levels are fine.


Typically when we speak about smaller than normal red blood cells, we talk about their volume. Assuming you mean small volume red blood cells (called a low MCV), there are many conditions that can cause this. I recommend that you follow-up with your doctor. The most common is iron deficiency, which is diagnosed not only by looking at blood iron levels but also ferritin, total iron binding capacity and sometimes transferrin saturation. Other possibilities include several inherited conditions, including thalassemia and sideroblastic anemia. Lead poisoning can more rarely cause anemia with a low MCV, as can vitamin B6 deficiency. More commonly people will have a chronic disease or inflammatory condition (such as rheumatoid arthritis) that will cause anemia with a low MCV. In other cases, the reason for this is unknown and the individual just has lower blood counts and smaller red blood cells for no apparent reason. The SPEP test looks for other blood disorders including multiple myeloma, which can sometimes cause anemia, especially in older people, though not necessarily a low MCV. There is clearly a wide range of possibilities, and though it is not necessarily a dangerous finding, it is important to make sure it doesn't represent an underlying undiagnosed condition since some can be quite serious. I would continue to follow-up with your doctor to undergo any additional testing that they think might be warranted in your case.

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