Unexplained Bruises? When to Be Concerned and What Could Be Causing Them
Systemic Diseases
Underlying illnesses may manifest with bruising: • Liver disease (e.g., cirrhosis) — reduced synthesis of clotting factors
• Kidney disease — platelet dysfunction or toxin-induced coagulopathy
• Blood cancers — leukemia may cause thrombocytopenia or abnormal vessel integrity
• Infection — sepsis can impair clotting mechanisms or cause disseminated intravascular coagulation (DIC)
• Autoimmune diseases — such as systemic lupus erythematosus (SLE) with secondary effects on blood and vessels
Vascular Conditions
Vasculitis—inflammation of blood vessels—can lead to purpura or ecchymoses. Conditions like Henoch‑Schönlein purpura (IgA vasculitis) may especially affect children, with bruising, abdominal pain, or kidney involvement. In older individuals, senile purpura (dermatoporosis) results from sun‑damaged, fragile skin that bruises easily.
Malnutrition and Nutrient Deficiency
Certain deficiencies, such as vitamin C (scurvy), vitamin K, vitamin B12, and folate, can impair blood vessel integrity or clotting factor production. Older adults or those with malabsorption, alcohol misuse, or restrictive diets may be at higher risk.
Cancer and Malignancy
Leukemia, lymphoma, or multiple myeloma may affect bone marrow production of platelets or clotting factors. Solid tumors can also cause coagulopathy or paraneoplastic syndromes leading to increased bruising.
Rare Causes
Rarely, unexplained bruising may be linked to inherited bleeding disorders like Glanzmann thrombasthenia, rare coagulopathies, or factitious disorder (self‑inflicted bruising). Psychological factors, such as stress or emotional abuse, may also play roles in some cases.
