Anemia

Anemia is when there is not enough healthy red blood cells to carry enough oxygen to the various parts of your body for it to function properly. Common symptoms include feeling fatigued and weak for no other apparent reason. It is common to feel tired for many reasons, but if it is persistent, and you are not sure at all as to why, it may be time to talk to your doctor.

The most common type is caused by iron deficiency. There are many other causes as well though, (though many of which cause the iron deficiency as well), such as intestinal disorders, pregnancy, insufficient diet, and family history.