## What are blood thinners used for? Let’s say you took one of the [COVID-19](https://ul.orna.me/KOge/librarybiomarker?id=3555) tests, such as a PCR test, and tested positive. It is not fully understood how [COVID-19](https://ul.orna.me/KOge/librarydisease?id=221) affects the body, but it has been proven that the virus can affect blood flow by causing thrombosis, or blood clots. A high fever during illness is also a serious risk factor affecting the blood, especially if the person does not drink enough water. People who are overweight, have diabetes, or are genetically predisposed to thrombosis are especially likely to clot. Signs of thrombosis: - Severe coughing, especially with blood - Cramps and sharp pain in the extremities - Sudden chest pain - Shortness of breath - Darkening and swelling of the skin at the site of the clot Urgent action should be taken if a person with COVID-19 develops any of the previous symptoms. ## How to choose the right anticoagulants The CDC recommends doctors use blood thinners for COVID-19 patients if they deem it necessary. They are selected on an individual basis depending on the health of the patient. Never seek to take a blood thinner without the guidance of your doctor. Blood thinner is sometimes used for patients with COVID-19 who experience the following: - Disorders in the blood clotting system - Lack of physical activity - Various blood diagnostics including coagulation, [fibrinogen](https://ul.orna.me/KOge/librarybiomarker?id=20), and D-dimer Patients diagnosed with thrombosis need to take blood thinners for at least three months at a therapeutic dose. For patients who have a mild form of the disease, but are at risk or have previously had thrombosis, anticoagulants may be prescribed in a prophylactic dose. It is important to remember that COVID-19 does not cause thrombosis in all patients. Doctors will only use blood thinners if it makes sense for that individual patient. ## Is aspirin just as effective? Many patients feel that aspirin is harmless, and those who get COVID-19 sometimes start taking it for preventive purposes since the drug not only thins the blood but also has anti-inflammatory and antipyretic effects. This should not be done without a doctor's prescription, because acetylsalicylic acid has a number of absolute contraindications including poor blood clotting, hyperacid gastritis, peptic ulcer, [diabetes](https://ul.orna.me/KOge/librarydisease?id=43), gout, [kidney](https://ul.orna.me/KOge/librarydisease?id=75) failure. Taking aspirin or other anticoagulants without the guidance of a doctor can lead to serious consequences by disturbing the normal blood clotting. Remember that both direct-acting and indirect-acting anticoagulants are very serious drugs, which, if taken incorrectly, may provoke life-threatening conditions. When taking blood thinners under the guidance of a doctor, drink lots of water and move during the day.