Paleness, also known as pale complexion or pallor, is an unusual lightness of skin color when compared with your normal hue. Paleness is caused by reduced blood flow or a decreased number of red blood cells. Paleness can be generalized (all over) or local. Local paleness usually involves one limb. You should see your doctor if you have sudden onset of generalized paleness or paleness of a limb.

Causes of Paleness
Anemia, a condition in which the body doesn’t produce enough red blood cells, is one of the most common causes of paleness. Anemia can be acute (sudden onset) or chronic (developing slowly).

Acute anemia is usually the result of rapid blood loss from trauma, surgery, bleeding stomach ulcers, or bleeding from the colon. Chronic anemia is very common. It can be caused by not having enough iron, B12 or folate in your diet. There are also genetic causes of anemia such as sickle cell disease and thalassemia (a genetic disorder that destroys red blood cells). Anemia that develops more slowly can be caused by diseases such as chronic kidney failure or hypothyroidism (when the body does not produce enough thyroid hormone). Certain cancers that affect the bones or bone marrow can also cause anemia due to slow blood loss over a period of weeks to months.

Things to Consider With Paleness
Skin color is determined by several factors, such as the amount of blood flowing to the skin, skin thickness, and the amount of melanin in the skin. Paleness also affects the inner membrane of the lower eye lids (conjunctivae), the palms of your hands and fingernails, your tongue, and the mucous membranes inside your mouth. According to the Journal of General Internal Medicine, paleness seen in the eyes is a reliable sign of anemia, regardless of race. It is also considered a sensitive indicator of severe anemia. Paleness can be a nonlife-threatening manifestation of emotions such as fear ("pale as a ghost"), or it can be a sign of serious medical problems such as severe anemia or frostbite.