Symptoms and Complications
The symptoms of anemia vary, depending on the degree of RBC loss or shortage.
Menstrual bleeding or iron deficiency tends to cause a mild chronic anemia with symptoms of fatigue, pallor, and weakness.
If anemia is due to major blood loss, such as in cases of severe GI bleeding caused by ulcers, you may feel dizzy and very weak, especially if you stand up suddenly.
Severe anemia can cause tissues and organs to be completely starved of blood and oxygen. When this happens, cells rapidly die in a process called ischemia.
In sickle cell anemia, RBCs, which are normally disc-shaped, become sickle-shaped. This abnormal shape of the cells causes them to get lodged in small blood vessels, stopping normal blood flow. People with this disease may get serious ischemia in their feet, sometimes requiring amputation. People with sickle cell anemia are at a high risk of stroke, since the sickle-shaped cells can easily clot together, forming masses that block blood flow in the brain's blood vessels.
For those with cancer, the most common symptoms of anemia are usually fatigue and shortness of breath. This makes it difficult to keep up usual energy levels and activities, and can have very negative effects on daily life.