Excessive or spontaneous bruising
Unexplained bruises, without any apparent physical trauma or injury, can be a symptom of acute onset leukemia. Excessive or spontaneous bruising results from a low number of platelets or clotting factors. Patients with leukemia may start spontaneously bleeding under the skin and result in bruise formation, obviously doing nothing. It can be anywhere but usually develop on the arms and legs.
In males, spontaneous bruising can also occur due to hemophilia A – another non-cancerous blood disorder that develops due to the deficiency of clotting factors.