I had a cbc that was normal. 7 days later, start bactrim for lyme. 5 days thereafter, cbc shows mild anemia (low: rbc, hgb, hematocrit), with normal iron/ferritin. low folate, normal mcv. is this folate defic. anemia or bactrim: aplastic anemia?

Could be a problem: Red blood cells live about 3 months, which means there should not be a big drop in a previously normal person's blood count after just 12 days. That means 90% of a person's red blood cells present today, should still be present 12 days from now. A big drop in RBC's, Hgb, and Hct would mean a need to recheck the blood test and/or look for some cause of loss of existing red blood cells.

NMS: But I would certainly correct the folate deficiency first and observe your response. Since folate def is not a common condition , one needs to investigate the cause for it also. If the folate correction does not remedy the anemia, one would then look for other causes.

May be neither: All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests. Having said that, it would have helped to have the actual values. As suggested but others, folate deficiency needs to be evaluated and corrected. Wish you good health! - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.