Acute lymphoblastic leukemia (ALL) is a type of cancer that affects the blood and bone marrow. It occurs when the body produces an excessive number of immature white blood cells, known as lymphoblasts. These cells crowd out healthy blood cells, leading to symptoms such as fatigue, frequent infections, and easy bruising. ALL is most common in children but can also occur in adults. Treatment for ALL typically involves chemotherapy, which uses powerful drugs to kill cancer cells and stop their growth. In some cases, a stem cell transplant may be necessary to restore healthy blood cell production. Early diagnosis and treatment are crucial for improving outcomes in patients with ALL.