The potential side effects of blood thinners include nosebleeds, prolonged bleeding after a cut, heavy menstrual periods, bleeding gums and bloody urine, according to Healthline. Blood thinners also cause dizziness, hair loss, rashes and muscle weakness in some people.
Blood thinners are used to prevent blood clots, states Healthline. Some blood thinners increase the amount of time it takes blood to clot, while others prevent blood cells from sticking together inside the blood vessels. Because blood thinners increase the risk of internal bleeding following an injury, anyone who takes them should seek medical attention after falling, even if there is no external bleeding. People taking blood thinners should also use caution when using sharp objects.