Why the blood count remains one of the most important tests
The blood count is one of the most requested tests in medical practice. It is often part of a routine check-up, requested before surgery or appears during an initial investigation when the person feels tired, weak, has a fever or is bleeding. Despite being a simple and low-cost test, the blood count can provide very important information about the functioning of the body.
In general, the blood count evaluates three main components of blood: red blood cells, white blood cells and platelets. Each of them has a different function. Red blood cells are responsible for transporting oxygen to tissues. White blood cells participate in the body's defense against infections. Platelets help with clotting, preventing excessive bleeding.
When the exam shows anemia and other clues about health
When we look at red blood cells, we can identify whether the person has anemia, especially when hemoglobin is low. It is important to understand that having anemia should never be considered normal. Furthermore, anemia is not a single disease, but can be the manifestation of different conditions or an underlying disease. It can arise due to iron deficiency, lack of vitamin B12, blood loss, inflammatory diseases, changes in the bone marrow or other causes. Therefore, in addition to observing whether hemoglobin is low, the doctor also evaluates characteristics of the red blood cells, which helps direct the investigation.
In iron deficiency, for example, it is common for red blood cells to be smaller and paler on examination. This condition may be related to inadequate nutrition, heavy menstruation, gastrointestinal bleeding or an increased need for iron at some stages of life. In case of vitamin B12 deficiency, red blood cells may appear enlarged. In addition to anemia, a lack of B12 can cause neurological symptoms, such as tingling, changes in sensitivity and difficulty with balance, in some cases.
Changes in white blood cells and platelets
White blood cells also deserve attention. They can increase in common situations, such as infections, inflammation and the use of some medications. But they may also be low, which may indicate a greater risk of infections or suggest problems in the production of these cells. In some situations, important changes in the number or appearance of white blood cells may raise the suspicion of hematological diseases, such as leukemia and lymphoma.
Platelets, in turn, help the blood to clot. When they are too low, there may be a greater tendency to bleed, such as bruises, gum bleeding, nosebleeds or very heavy menstruation. When they are very high, depending on the context, they may be associated with inflammatory processes, iron deficiency or bone marrow diseases. Therefore, interpretation must always consider the patient's history and other complementary exams.
The role of blood counts in early diagnosis
An important point is that some blood diseases can be discovered even before they cause clear symptoms. There are cases in which a person does a routine blood count and the exam shows significant anemia, a drop in platelets or a significant change in white blood cells. From there, the doctor requests a more detailed investigation and can diagnose more serious diseases, such as leukemia. In these cases, routine examination does not prevent the disease, but it may allow it to be identified earlier, before serious complications occur.
Even so, many people only seek care when symptoms appear. This happens for several reasons: lack of time, fear of discovering an illness, difficulty accessing the healthcare system or the feeling that tests are only necessary when something is clearly wrong. The problem is that some changes can evolve silently for weeks or months. Persistent tiredness, paleness, unexplained weight loss, recurrent fever, frequent infections, bruises for no apparent reason and unusual bleeding are signs that should not be ignored.
It is important to remember that the blood count does not give all the answers alone. It is a photograph of the blood at that moment and needs to be interpreted by a healthcare professional. An altered result does not necessarily mean a serious illness. Likewise, an apparently normal result does not exclude all health problems. The value of the exam lies precisely in guiding medical reasoning and indicating when it is necessary to investigate further.
Another important concept is that anemia does not transform into leukemia. Most of the time, anemia has other causes, such as iron deficiency, vitamin deficiency or blood loss. However, when anemia is accompanied by other changes in the blood count, such as a drop in platelets or important changes in white blood cells, it is essential to take a more careful look at the diagnosis.
Carrying out regular monitoring, maintaining routine appointments and discussing the results with a professional are simple attitudes that can make a difference. A blood count is just a test, but it is often the first sign that the body needs attention. When well interpreted, it can help identify nutritional deficiencies, infections, coagulation disorders and hematological diseases, contributing to earlier diagnoses and more appropriate treatments.
*Text written by hematologist Pedro Neffá (CRM 172414/SP | RQE 10093 | RQE 100936), hematologist at Vila Nova Star and São Luiz Itaim hospitals, Rede D'Or
Iron deficiency anemia: understand diagnosis
Source: CNN