Blood thinners: what you should know

Blood thinners are medicines used to treat and prevent blood clots. Blood travels through blood vessels in liquid form, bringing oxygen and nutrients to tissues throughout the body.When blood clots form in the body, they prevent normal blood flow from reaching tissues and can lead to tissue death such as heart attack, stroke and pulmonary embolism.

While blood thinners can be life-saving medications, they carry bleeding risks. This article discusses the types of blood thinners, their medical uses, and side effects.

What is a blood thinner?

Blood thinners are medicines that treat and prevent blood clots. Blood clots are red blood cells, platelets, fibrin (a type of protein) and other proteins.

Blood clotting is an extremely important function of the body to prevent bleeding. If there is no blood clotting, the small incision can cause severe, prolonged bleeding.

Thrombosis and Embolism

Another word for a blood clot is “thrombus,” but when a blood clot travels to another place in the body, it’s called an “embolus.” For example, a “pulmonary embolism” is a blood clot from a deep vein in the leg to the pulmonary artery.

Blood clots form through two important processes: coagulation Cascade and platelet activation. Blood thinners work by targeting the steps in each process.

In the coagulation cascade, damaged tissue triggers a chain of events that activate several proteins in the blood called clotting factors. These proteins are activated through a series of steps that ultimately activate fibrin. Fibrin is a protein formed during blood clotting that helps stop blood flow.

Another important component of blood clots are platelets. Damaged tissue activates platelets in the blood. Activated platelets attract other platelets, which stick to each other to plug the wound and stop the bleeding.

red and white clots

Blood clots rich in red blood cells and fibrin are called “red clots,” while colorless blood clots rich in platelets are called “white clots.” Red clots are found in veins (such as leg veins), while more white clots are found in arteries (such as the coronary arteries of the heart). The distinction between red and white is based on the color and composition of the clot, but all clots contain varying amounts of platelets, fibrin, and red blood cells.

Why Prescribe Blood Thinners?

Broadly speaking, blood thinners are used to treat blood clots or prevent blood clots from forming when they are dangerous to the body. Here are some specific situations that may require blood thinners:

  • deep veins thrombosis (DVT), blood clots in the veins of the legs
  • Pulmonary embolism (PE), a blood clot in a blood vessel in the lung
  • Acute Coronary Syndrome, a blood clot in a coronary artery that causes a heart attack
  • artificial heart valve
  • left ventricle thrombusblood clot in the heart
  • acute limb ischemiablood clots in leg arteries
  • acute mesenteric ischemiablood clots in the arteries that supply the intestines
  • Atrial fibrillation, an irregular and abnormally fast heartbeat
  • hypercoagulable stateConditions that cause thick blood
  • certain pregnancy-related conditions
  • Prophylaxis of blood clots after certain surgeries

How do blood thinners work?

In general, all blood thinners work by blocking or inactivating the parts of the system that form blood clots. These drugs work by binding to proteins involved in the coagulation cascade or proteins on the surface of platelets.

anticoagulant Drugs target the coagulation cascade, while antiplatelet drugs target platelet activation.

Types of blood thinners


Anticoagulants Blood thinners target various proteins in the coagulation cascade. These drugs are used to treat red blood clots, such as deep vein thrombosis and pulmonary embolism, and to prevent atrial fibrillation and stroke with mechanical heart valves.

Anticoagulants are also used in acute arterial coagulation processes (eg, heart attack, acute limb ischemia, and acute mesenteric ischemia). Examples of anticoagulants include:

  • coumarin (Warfarin)
  • enoxaparin (low molecular weight heparin)
  • Factor X inhibitors, such as Eliquis (Apixaban) and Xarelto (Rivaroxaban)
  • direct thrombin inhibitors, such as Akova (Argatroban), Hemangioma (bivalirudin), and Pradaqsa (dabigatran)
  • Tissue plasminogen activators, such as active agent (alteplase), TNK enzyme (tenecteplase), and reinjury enzyme (replase)


Antiplatelet drugs are drugs that target platelet activation and aggregation. They are commonly used to treat and prevent strokes and heart attacks.

Antiplatelet drugs are also used to protect stents placed in the coronary arteries and other arteries of the heart, such as the carotid and leg arteries in peripheral arterial disease.

Examples of antiplatelet agents include:

  • aspirin
  • P2Y12 receptor blockers, such as Plavix (Clopidogrel), efficient (Pragre), and brilinta (ticagrelor)
  • Phosphodiesterase inhibitors such as Agrenox (dipyridamole) and centipede (Cilostazol)
  • GIIb/IIIa inhibitors, such as Leopold (abciximab), integrin (eptifibatide), and Agrasta (Tirofiban)

side effect

Unsurprisingly, the main side effect of blood thinners is bleeding. People who take blood thinners will notice that cuts or cuts take longer to stop bleeding and bruise more easily. But serious bleeding, such as bleeding from the gastrointestinal tract or brain, can occur. These bleedings can be life-threatening.

Each specific drug has a range of side effects, ranging from nausea, constipation and headaches to shortness of breath and severe allergic reactions.

natural blood thinner

Some foods and supplements are thought to have some blood-thinning properties. However, they are not regulated by the U.S. Food and Drug Administration (FDA), and the concentrations of active compounds in supplements are not consistent.

Always discuss with your healthcare provider any supplements you are taking or considering, as they can interfere with other medications. Supplements should never be used as a substitute for prescription blood thinning medications.

Here is some evidence of blood thinning properties:

  • cranberry
  • Angelica
  • Fenugreek
  • white chrysanthemum
  • garlic
  • ginger
  • ginkgo
  • red clover
  • turmeric
  • white willow


Blood thinners are important medications used to treat and prevent blood clots. These include anticoagulants and antiplatelet drugs. The benefits of taking blood thinners must always be weighed against the risk of serious bleeding.

VigorTip words

If you are prescribed a blood thinner, be sure to watch for signs of bleeding, such as red or black stools, severe headache, dizziness, and fainting. Seek immediate medical attention if you notice any of these symptoms. Also be sure to discuss any supplements you are taking with your healthcare provider, as many of them can affect the way your medicines work.

Frequently Asked Questions

  • How long does blood thinner stay in your system?

    This depends on the type of blood thinner and can range from a few hours to a few days. The blood-thinning effects of warfarin, aspirin, and Plavix (clopidogrel) can last for several days, while Eliquis (apixaban) and Xarelto (rivaroxaban) go away in about a day. Lovenox (low molecular weight heparin) disappears after about 12 hours.

  • How long should you take blood thinners?

    It depends on why your healthcare provider prescribed blood thinners in the first place. After a heart attack or ischemic stroke, most people can expect to take at least one blood thinner for life. People taking blood thinners to treat induced deep vein thrombosis may only need to take them for three months.

  • What pain relievers are safe for blood thinners?

    NSAID (non-steroidal anti-inflammatory drug) pain relievers such as Advil and Motrin (ibuprofen) and Aleve (naproxen) have blood-thinning properties and should not be combined with blood thinners. This is especially true for aspirin because these other NSAIDs can compete with the same binding sites that aspirin uses and render aspirin ineffective.

    Tylenol (acetaminophen) is generally a safe over-the-counter pain reliever that can be taken with blood thinners.