Megaloblasts are large, abnormal red blood cell precursors found in the bone marrow. They are characterized by their oversized nuclei and are typically associated with certain types of anemia, particularly megaloblastic anemia. This condition often results from a deficiency in essential nutrients like vitamin B12 or folate, which are crucial for proper red blood cell formation. In a healthy individual, red blood cells develop from smaller, normal-sized cells. However, in the presence of megaloblasts, the maturation process is disrupted, leading to ineffective red blood cell production. This can result in symptoms such as fatigue, weakness, and pale skin due to reduced oxygen-carrying capacity in the blood.