Definition: Anemia is a lack of red blood cells, usually one or more in count, causing anemia. It can be caused by many factors including iron deficiency, vitamin deficiencies, and other conditions that affect your body's ability to absorb oxygen efficiently. The cause typically lies at the cellular level. Anemia affects vital functions like growth, immune system response, and nerve function. If left untreated, it can lead to complications such as fatigue, shortness of breath, and่ดซ่กๆงๅฟ่็ ใ