Bruises can appear on our skin for many reasons and appear when tiny blood vessels under the skin are torn or ruptured. The most common reason for a bruise is a blunt impact on your skin, in which cases most people will expect to find a bruise in the location of the impact within a few hours to a couple of days. Sometimes these impacts are hard enough that you can know right away that a bruise is going to form and other times they can be caused by a minor impact and seemingly appear out of the blue until you remember you did in fact have an impact on that area recently. Bruises can also be an indication of something going on under the skin that has caused trauma to the area such as a sprain or a fracture. For the most part, bruises will fade on their own over the course of a few days to a few weeks depending on the size and severity of the bruise and the injury sustained. However, sometimes a bruise can be an indication of a more serious issue that requires medical attention. A serious bruise that requires medical attention is one where the area of the bruise is large, the bruise appeared without injury, there are no signs of improvement to the bruise after a week, the bruise increases in size, additional bruises appear, the bruise is over a joint or you have additional symptoms such as a fever or bleeding from the mouth or nose. Some medications, as well as some health conditions, can increase your risk of bruising, making you more susceptible to having a bruise form from a blunt impact. Bruises do not break the skin or cause bleeding however a bruise can form around an area of the skin that has broken if the cut was the result of a severe impact.