CBSE Class 9 Answered

The doctor listens to the symptoms mentioned by the patient and orders different types of blood and/or stool test. Those reports combined with the symptoms will help the doctor to detect the disease. During illness, there may be variations in the pulse rate. Throat is checked to determine if there is any infection there.

You will get a better idea from the following example - If a patient is having symptoms such as fatigue or weakness or has an infection, inflammation, bruising, or bleeding, then the doctor may order a complete blood count to help diagnose the cause. Significant increases in WBCs may help confirm that an infection is present and suggest the need for further testing to identify its cause. Decreases in the number of RBCs (anemia) can be further evaluated by changes in size or shape of the RBCs to help determine if the cause might be decreased production, increased loss, or increased destruction of RBCs. A platelet count that is low or extremely high may confirm the cause of excessive bleeding or clotting and can also be associated with diseases of the bone marrow such as leukemia.

Many conditions will result in increases or decreases in the cell populations. Some of these conditions may require treatment, while others will resolve on their own. Some diseases, such as cancer (and chemotherapy treatment), can affect bone marrow production of cells, increasing the production of one cell at the expense of others or decreasing overall cell production. Some medications can decrease WBC counts while some vitamin and mineral deficiencies can cause anemia. The CBC test may be ordered by the doctor on a regular basis to monitor these conditions and drug treatments.