Increased bleeding is the most common side effect of blood thinners, states Healthline. This side effect can manifest in the form of nosebleeds, heavy menstrual bleeding, blood in the urine or feces, bleeding gums or prolonged bleeding following an injury.
Blood thinners reduce the risk of stroke and heart attack by preventing blood clots, explains Healthline. They do this by preventing platelets from sticking together inside the blood vessels. Heparin, enoxaparin and warfarin are some of the most common blood-thinning medications prescribed by medical professionals.
Heparin is used to prevent blood clots or keep existing clots from getting bigger, notes MedlinePlus. The drug is given as an injection, so some redness or pain can occur at the injection site. More serious side effects include chest pain, excessive tiredness, unusual bleeding, sudden confusion and difficulty breathing.
Enoxaparin inhibits the effects of certain proteins, reports MedicineNet. This drug is often used to prevent clots in people who have had joint replacement surgery or abdominal surgery. Side effects of enoxaparin include diarrhea, bleeding, fever, nausea and fluid retention.
Warfarin blocks the effects of clotting factors that are dependent on vitamin K, explains the American Heart Association. This prevents the formation of clots and keeps existing clots from growing. One of the complications associated with warfarin use is excessive bleeding.