Leukemia is a cancer that originates in the bone marrow, the soft, spongy tissue inside bones. It involves the uncontrolled growth of abnormal blood cells, typically white blood cells. Easy bruising and bleeding are common symptoms that often prompt individuals to seek medical attention.
How Bruises Form Normally
Bruises form when small blood vessels, called capillaries, near the skin’s surface are damaged. This causes blood to leak out and pool in the surrounding tissues, creating a visible mark that can range in color from red to purple, black, or blue. The body’s natural response involves platelets, tiny cell fragments in the blood. Platelets rush to the site of damage, clustering to form a plug that helps seal the injured blood vessel and stop the bleeding, a process called hemostasis.
Leukemia’s Effect on Blood Cell Production
Leukemia disrupts the normal process of blood cell formation within the bone marrow. The bone marrow produces an excessive number of abnormal white blood cells. The proliferation of these abnormal cells leads to overcrowding in the bone marrow.
This crowding suppresses the production of healthy blood cells, especially platelets. The abnormal cells impede the development of megakaryocytes, which are the large bone marrow cells responsible for producing platelets. This directly results in a decreased number of circulating platelets.
Why Low Platelets Cause Bruising
A reduced number of platelets in the blood is known as thrombocytopenia. Platelets are crucial for blood clotting; without an adequate supply, the blood’s ability to form clots is significantly impaired. When the platelet count falls, the risk of bleeding and bruising increases.
With fewer platelets available to plug damaged blood vessels, even minor impacts or pressure can cause blood to leak under the skin more easily and extensively than usual. This leads to the appearance of easy bruising, which may be larger or occur in unusual areas of the body. Bruises are a prominent symptom of low platelet counts in leukemia because the body cannot effectively stop internal bleeding from everyday bumps.
Other Bleeding Signs to Recognize
Beyond easy bruising, low platelet counts can manifest in several other bleeding-related signs. Petechiae are tiny, pinpoint red or purple spots on the skin, caused by bleeding from capillaries.
Individuals may also experience frequent or prolonged nosebleeds, or bleeding from the gums, particularly during brushing. Minor cuts might bleed for an unusually long time. Women may notice unusually heavy or prolonged menstrual periods. Blood in urine or stool is another potential sign of internal bleeding due to insufficient platelets.