Paling causes the face and extremities to lose color by decreasing blood flow to these areas of the body. This phenomenon occurs mainly in the context of shock-induced circulatory centralization. Sudden pallor ensures survival by drawing blood from the extremities to the vital organs.
What is pallor?
Paleness causes the face and extremities to lose color by decreasing blood flow to these areas of the body. Often, pallor has disease value, such as in the case of leukemia. A pale patient loses color in the face and extremities. Usually this loss of color is due to a decrease in blood volume, which can have various causes. Often pallor has disease value, for example, in the case of leukemia, coronary heart attacks and renal insufficiency. Even a cold can be accompanied by pallor. The same applies to blood loss. Paleness is not a disease in its own right, but it is a symptom. Sudden pallor is always a phenomenon of blood loss. The body withdraws blood from the extremities to supply it to the vital organs. The opposite of this phenomenon is blushing. Especially in the facial region, blood volume increases during blushing. The cause of this phenomenon is a sudden expansion of blood vessels in the affected skin region.
Function and task
With paling, the organism wants to ensure survival. Paleness in this context is usually associated with centralization of the circulatory system. Such centralization is a vital adaptation process of the blood supply. Blood is thereby drawn from the periphery of the body to the vital centers. In particular, adequate blood supply to the heart and brain is thus ensured by centralization. The red blood cells in the blood transport oxygen. If this oxygen does not reach the organs in sufficient quantities, organic damage sets in. To prevent such damage, the organism secretes catecholamine. Catecholamines are biogenic amines such as the neurotransmitter dopamine or the substances adrenaline and noradrenaline. The release of these catecholamines takes place primarily in the adrenal glands and in the central nervous system. In most cases, the release causes an accelerated heartbeat in addition to pallor. Sweating is also common. Centralization via catecholamines is mainly observed in the context of physiological shock. In this case, the body tries to counteract a lack of blood volume. This deficiency occurs, for example, in the context of bleeding, fluid loss, or sepsis. Psychological and neurological shocks, however, can also initiate centralizations. In neurogenic shocks, for example, stimulus transmission in the circulatory and capillary systems is disrupted. In these contexts, shock and the associated pallor is an acute stress response. The automatically released catecholamines cause the peripheral blood vessels to contract. The blood volume thus retracts into the large vessels of the center, which is especially important for survival during hemorrhage. In addition to the causes mentioned above, centralization of the circulation and the associated pallor may also be related to hypotension. In this phenomenon, the blood pressure is below 100/60 mmHg. Hypotension often occurs in the context of heart disease. However, they may also be associated with infections or glandular dysfunction. Another cause of centralized circulation is anemia. This blood deficiency can occur as a result of bleeding. However, tumors, infections or immune and enzyme defects are also partly responsible for anemia. In the case of circulatory centralization, pallor usually affects the mucous membranes in addition to the outer skin. Pallor may also occur in the context of smoking and in this context is due to similar life-sustaining effects as those described here. Some shocks and centralizations are such a reaction to certain poisons. In this context, there is talk of anaphylactic shocks, in which histamine is released. As a result of this release, the vessels dilate, the blood pressure drops and there is a lack of blood. To ensure survival, circulatory centralization is also required in this case.
Diseases and ailments
Since pallor is merely a symptom and not a specific disease, diagnosis in this case turns out to be difficult. Paleness is nonspecific because centralization of the circulation can have a wide variety of causes. Above, some of these causes were mentioned, but the list is far from being exhausted. Various syndromes, injuries, organ diseases, and infectious diseases are associated with paling. The medical history is therefore an important starting point for the physician to determine the cause of pathological paling. Relevant in this context is, for example, when exactly the pallor occurs. Equally relevant are the patient’s pulse and blood pressure. A blood test can detect anemia, for example. However, anemia can also have various causes. The diagnosis is therefore often not completed with the blood test. Depending on the suspicion, laboratory diagnostics may be followed by ECG examinations or ultrasound examinations of the spinal cord. In this way, the suspicion of coronary heart disease and leukemia can be investigated. To treat pallor, the physician addresses the underlying condition.
