Anemia is a condition where your red blood cells are not healthy and fail to effectively transport oxygen to your vital organs. Like sleep apnea, this can lead to a less than ideal level of oxygen available to your body. Although there are over 400 recognized causes of anemia, there are two causes you should consider right off the bat. Iron deficiency is common, especially in pre-menopausal women. The second is pernicious anemia, which is the inability to digest vitamin B12. Discuss this with your doctor. If you are otherwise healthy and your doctor is supportive, consider trying an iron supplement (there are iron supplements available that do not cause constipation). To get past the B12 digestion issue, a B12 tablet is available that dissolves under the tongue. Some people will also have B12 injections. There is obviously a lot more to this issue, but this is just intended to get you thinking.