What would you expect to see in a diseased cell as apposed to a normal cell?

Blood will contain erythrocytes and the white blood cell population. In disease there will be an elevated count of white blood cells such as neutrophils and monocytes compared to normal, so if you observe this difference it is indicative of disease. Haemorrhagic disease will show lysed erythrocytes, while parasitic disease such as malaria would show irregularly shaped red blood cells whith characteristic morphology as the infecting parasite grows. Allergic or helminth infection would show an increased number of eosinophils, basophils and mast cells. Lymphocytes which would be in transit from lymphnodes to the site of infection will appear larger than normal. There may be a higher population of dendritic cells. If the disease is affecting the white blood cells in particular, there may be an uncharacteristic absence, or again their size is increased compared to normal. It depends whether the infection is viral, bacterial or helminthic.