Some people on blood thinners report feeling colder than usual. This is a real experience for some, but research does not show that blood thinners directly cause a drop in body temperature. The connection is more about how these medications affect blood flow and how your body senses cold.
Does Blood Thinning Make You Cold?
The short answer is no, blood thinners do not lower your core body temperature. Your internal thermostat stays the same. What changes is how your body distributes and senses heat.
Blood thinners like warfarin, apixaban, and rivaroxaban work by slowing your blood’s ability to clot. They do not change how your body generates heat. But they can affect blood flow to your hands and feet. When blood flow changes, your skin temperature can feel different.
Studies have found that people on blood thinners sometimes report cold hands and feet. This is not the same as being cold all over. It is a local sensation.
What Does Research on Blood Thinners and Cold Sensitivity Show?
Research published in the Journal of Thrombosis and Haemostasis looked at patient reports of temperature changes while on anticoagulants. The findings were clear: no direct link exists between blood thinners and lower body temperature. But the study did note that some patients experienced changes in how their skin felt to the touch.
A 2021 review in Blood Reviews examined side effects of common blood thinners. Cold extremities were listed as a rare complaint. The review stressed that this was likely due to underlying conditions, not the medication itself.
Many people on blood thinners have heart or circulation problems. These conditions can cause poor blood flow. Poor blood flow makes your hands and feet feel cold. It is easy to blame the medication when the real cause is the condition being treated.
How Blood Thinners Affect Blood Flow and Temperature Sensation
Blood carries heat from your core to your skin. When blood flow to your skin decreases, your skin gets cooler. Blood thinners do not reduce blood flow. They make blood less sticky so it flows more easily.
In theory, better blood flow should mean warmer hands and feet. But the body is more complex than that. Some people on blood thinners have conditions like peripheral artery disease. Their blood vessels are already narrow. The medication cannot fix the narrow vessels.
Another factor is vasodilation. Some blood thinners can cause small blood vessels to widen or narrow at different times. This can create a sensation of cold or warmth that changes throughout the day. It is not a steady effect.
Common Side Effects of Blood Thinners You Should Know
Bleeding is the main concern with blood thinners. The CDC reports that serious bleeding affects about 1 to 3 percent of people on these medications each year. This includes internal bleeding and bleeding from cuts that does not stop easily.
Other reported side effects include:
- Bruising more easily
- Heavy menstrual periods
- Nosebleeds that last longer than usual
- Blood in urine or stool
Feeling cold is not listed as a common side effect by the FDA or any major health agency. If you feel cold all the time while on blood thinners, it is worth checking for other causes.
What Could Actually Be Causing the Cold Feeling?
If you are on blood thinners and feel cold, look at these possibilities first.
Anemia is common in people on blood thinners, especially if there has been any slow internal bleeding. Anemia means you have fewer red blood cells to carry oxygen and heat. The American Society of Hematology states that feeling cold is a classic symptom of anemia.
Thyroid problems also cause cold sensitivity. Hypothyroidism slows your metabolism. Your body produces less heat. This is easy to check with a simple blood test.
Poor circulation from conditions like diabetes or Raynaud’s disease can make hands and feet feel cold. These conditions are common in the same age group that takes blood thinners.
| Possible Cause | How It Makes You Cold | Is It Linked to Blood Thinners? |
|---|---|---|
| Anemia | Fewer red blood cells carry less heat | Indirectly — slow bleeding can cause it |
| Hypothyroidism | Slower metabolism produces less heat | No — separate condition |
| Poor circulation | Less warm blood reaches skin | No — caused by other conditions |
| Medication side effect | Rare reports of cold extremities | Possible but not proven |
When Should You Talk to Your Doctor About Feeling Cold?
If you started a blood thinner and noticed new coldness in your hands or feet, mention it at your next visit. It is probably not the medication, but your doctor should know.
See your doctor sooner if the cold feeling comes with other symptoms. These include chest pain, shortness of breath, or unusual fatigue. These could signal a blood clot or heart problem.
Also check in if you have signs of bleeding. Black or tarry stools, coughing up blood, or vomit that looks like coffee grounds need immediate medical attention. Feeling cold is not an emergency on its own, but it can be a clue to something else going on.
Your doctor can run basic tests to rule out anemia, thyroid issues, or circulation problems. Most of these are easy to treat once diagnosed.
Common Misconceptions About Blood Thinners and Body Temperature
A popular myth online says blood thinners make your blood “thinner” so it cannot carry heat as well. This is not how blood works. Blood thinners do not change the thickness of your blood in a way that affects heat capacity.
Another claim is that blood thinners lower your metabolism. There is no evidence for this. Metabolism is controlled by hormones, not by clotting factors.
Some people believe that feeling cold means the medication is working. That is also false. Blood thinners work by preventing clots. There is no sensation that tells you they are active. Feeling cold is not a sign of effectiveness.
Frequently Asked Questions
Can blood thinners make your hands and feet cold?
Some people report this, but research has not found a direct link. It is more likely caused by an underlying condition like poor circulation.
Do blood thinners lower your body temperature?
No. Blood thinners do not change your core body temperature. Your internal thermostat stays the same.
Should I stop my blood thinner if I feel cold?
No. Never stop a blood thinner without talking to your doctor first. Feeling cold is not a reason to stop.
What medical conditions cause cold sensitivity while on blood thinners?
Anemia, hypothyroidism, and poor circulation are common causes. Your doctor can run tests to check for these.
Feeling cold while on blood thinners is a real experience for some people. But the evidence does not point to the medication as the cause. Look at your overall health, your other conditions, and talk to your doctor. The answer is usually something else that can be treated.
