Blood Thinning Medicines

It’s important to understand how blood thinners work and how to take them.

Blood clotting, carried out by platelets in the blood, is a normal body function. For example, if you cut yourself, your blood clots to seal up the wound. But certain conditions and heart disease risk factors — such as high cholesterol, high blood pressure, diabetes and smoking — can cause platelets to clump together more easily.

When a blood clot forms in your blood stream, it can cause a life-threatening heart attack or stroke.

How Blood Thinners Work

Blood thinners, also called antiplatelet medicines, affect your body’s ability to form blood clots. If you've had a heart attack, stroke or you have a stent placed in an artery, most often your doctor will prescribe blood thinners to lower your risk of a heart attack or stroke.

How to Take Blood Thinners

Your cardiologist or nurse will explain how to take your medicine. If something is unclear, don’t be afraid to ask for more information.

You should:

  • Ask how long you'll be taking the medicines. You may be on more than one medicine for a year or more, and you may take aspirin for an extended time.
  • Always talk to your cardiologist or nurse before you stop or change the way you take blood thinners.
  • If you forget a dose, take it later that day. If you miss taking it entirely, don't take two doses the next day; talk to your doctor.
  • Tell all your healthcare providers you're taking blood thinners, particularly when you get a new prescription.
  • Before you have dental work or surgery, ask your dentist or surgeon if you should stop taking blood thinners.


Have questions about medicines you're taking? You can schedule a free, private consultation with a pharmacist at our Health Library & Resource Center.

Blood Thinners FAQ

Are there any physical changes I should be aware of?
When you take blood thinners, you'll bleed and bruise more easily — that just means the medicines are working.

Do I need to change my activities while I’m taking blood thinners?
You can still engage in most activities while taking blood thinners, but you should take some extra precautions:

  • Be cautious about activities, including high-risk sports, that could result in injury. Always wear proper safety gear, such as a bike helmet when cycling.
  • Wear protective gloves when working with tools, including gardening shears or other sharp instruments.
  • Take special care when shaving or when trimming your hair or nails.
  • Use a soft toothbrush to prevent bleeding gums.
  • Always wear shoes to prevent foot injuries.


If you’re not sure about a particular activity, ask your doctor.

When should I call my doctor?
Call your doctor if you:

  • Have headaches, dizziness, chest pain, stomach upset or pain, diarrhea, constipation, muscle pain or severe back pain.
  • Have blood in your urine or stool (dark or black-colored stools) or you get nosebleeds that are hard to stop.
  • Throw up brown or coffee-colored liquid.
  • Have excessive bruising or bleeding that won’t stop.
  • Feel very tired, weak or short of breath, or you look pale.
  • Have a sudden, severe headache or you're confused.
  • Have fever, chills or yellowed skin or eyes.


What happens if I cut or scrape myself by accident?
It's likely that a cut will take longer to stop bleeding. Put pressure on the bleeding area for five minutes or until the bleeding stops. In addition, there are several over-the-counter products that can help stop bleeding more quickly. Talk to your doctor to learn more.

Are there other recommendations for people taking blood thinners?

  • Take your blood pressure regularly. Your doctor or nurse will tell you about the equipment you need, how to take your blood pressure, and how often to do it. If your blood pressure is above 135/85 mm Hg, call your doctor. The Health Library & Resource Center at El Camino Health offers free blood pressure monitoring.
  • Plan ahead when you travel. Always bring an extra dose or two of your medicine in case of travel delays. And, when flying, make sure you pack your medicines in a carry-on bag in case your luggage is lost.


Are there any programs to help with the cost of medicines?
There are support programs that can help you with the cost. Talk to your doctor or nurse to learn more.