Hello, Thanks for writing to us. Some of the causes of bruising for no reason include age, medication, or serious disease. Bruising for no reason may be a signal to consult a healthcare professional. Meningoccocal diseases, such as meningitis and meningococcemia, are potentially fatal conditions that can cause easy bruising. Hemophilia and other genetic conditions that impair blood clotting make one prone to bruising and internal bleeding that can be life-threatening. Clotting problems can also be an acquired condition, as in the case of cirrhosis of the liver. Leukemia, von Willebrand disease. I do hope that you have found something helpful and I will be glad to answer any further query.