Anticoagulants are important medicines that help stop blood clots and keep our blood flowing smoothly. They are used for many different reasons. Here are some of the main situations where anticoagulants are used:

1. Atrial Fibrillation: This is a heart condition where the heart beats irregularly. People with this condition have a higher chance of having a stroke because of blood clots. Anticoagulants can lower this risk a lot.

2. Deep Vein Thrombosis (DVT): DVT happens when a clot forms in a deep vein, often in the leg. Anticoagulants can stop the clot from getting bigger and can help reduce the risk of it moving to the lungs.

3. Pulmonary Embolism: This occurs when a blood clot travels to the lungs. Anticoagulants are really important for treating this and preventing new clots from forming.

4. Mechanical Heart Valves: Some people have artificial heart valves. They often need anticoagulants to avoid blood clots around the valve.

5. Venous Thrombosis after Surgery: After certain surgeries, like hip or knee replacements, anticoagulants can help reduce the risk of clots forming.

In short, if you have any of these health issues, anticoagulants can really make a difference!