Feeling constantly fatigued can be tough, especially when you’re already living with a serious health condition like pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH). If you have certain types of PH or PAH, like chronic thromboembolic pulmonary hypertension (CTEPH), you may be prescribed blood thinners to reduce the risk of blood clots and other related conditions. But could the blood thinners you’re taking be contributing to your exhaustion?

A myPHteam member who was taking blood thinners for PH asked, “Do blood-thinning drugs make your energy level low? They made me so sick and exhausted that I couldn’t even get out of bed.”

Fatigue goes beyond feeling tired. It involves persistent low energy that interferes with daily life. People with PH and PAH can experience fatigue for many reasons. For example, they may get limited exercise and have reduced oxygen levels, shortness of breath, problems with sleep, and other health conditions.

In this article, we discuss what blood thinners are, which people with PH or PAH may take them, and how they’re related to fatigue.

What Are Blood Thinners?

Despite the name, blood thinners don’t actually thin your blood. Instead, these medications make it more difficult for your body to form blood clots that might cause a heart attack, stroke, or block blood vessels.

People with PH or PAH may take blood thinners if they have an increased risk of blood clots due to medical conditions such as:

• Blood vessel disease, including heart disease
• Atrial fibrillation (irregular heartbeat)
• Heart valve replacements
• Surgery

People with PH or PAH may take blood thinners if they have an increased risk of blood clots due to other medical conditions like heart disease.

CTEPH is a type of PH that causes an increased risk of blood clots. It also causes increased pressure in pulmonary arteries, which puts stress on the heart and arteries over time and can weaken it. This stress can cause a disturbance in blood flow that increases the risk of blood clots. A blood clot that starts in deep veins can get lodged in the lungs, causing a pulmonary embolism, which could make PH symptoms worse.

Due to their high risk of blood clots, people with CTEPH may need to be on lifelong blood thinners. However, not everyone with PH or PAH should be on blood thinners.

Depending on your overall health status and other health conditions, your doctor may recommend that you take blood thinners for a few months, a few years, or the rest of your life. For example, if you develop a blood clot in your leg, you may be on a blood thinner for three or more months. After a heart attack, you may be on a blood thinner for six months to over a year. People with CTEPH may need to take lifelong blood thinners.

Types of Blood Thinners

There are two main types of blood thinners — anticoagulants and antiplatelets.

Anticoagulants interrupt the body’s process of making clots. The oldest anticoagulant is warfarin. It works by blocking vitamin K, which is used to make many of the proteins involved in forming blood clots. Although warfarin is very effective at preventing blood clots, it has several food and drug interactions and requires frequent blood tests and dose adjustments.

Direct oral anticoagulants (DOACs) are newer anticoagulants that don’t have as many food and drug interactions as warfarin. Warfarin dosing must be adjusted for each person based on regular blood tests. DOACs use fixed doses and don’t require routine blood monitoring, but the starting dose is still chosen based on factors like kidney function, age, weight, and other medications.

DOACs work to block parts of the pathway that cause blood clots. One DOAC, dabigatran, directly blocks thrombin (factor IIa). Other DOACs, including rivaroxaban, apixaban, and edoxaban, directly block factor Xa, another protein needed for blood to clot.

Antiplatelet medications prevent the small blood cells called platelets from sticking together to form a clot. Examples of antiplatelet medications include:

• Aspirin
• Clopidogrel
• Prasugrel
• Ticagrelor

Side Effects of Blood Thinners

Fatigue is not usually listed as a common side effect of most blood thinners. The side effects depend on the specific blood thinner you take. However, if you experience new or worsening fatigue on a blood thinner, you may have low-iron anemia from blood loss. If you notice this symptom, contact your healthcare provider.

Some more common side effects of blood thinners include:

• Nosebleeds
• Bleeding gums
• Bruising
• Upset stomach
• Nausea
• Diarrhea
• Decreased appetite
• Hair loss
• Lightheadedness or dizziness

Blood thinners make it take longer for your blood to clot. This process can increase your risk of internal bleeding, which could be life-threatening in some cases. It is important to be aware of serious symptoms, such as:

• Blood in your urine
• Black, tarry stool
• Red blood in your stool
• Vomit that looks like coffee grounds
• Nosebleeds that don’t stop
• Difficulty breathing
• Heavy bleeding during a menstrual period
• Any bleeding that won’t stop

Can Blood Thinners Cause Fatigue?

If you have noticed fatigue and increased tiredness while taking a blood thinner, you aren’t alone. Both doctors and people taking blood thinners have reported fatigue as a side effect of blood thinners. Scientists have therefore conducted several medical studies to find out if fatigue is related to blood thinner use.

A 2005 study found that short-term use of warfarin was not associated with fatigue.

The results of a 2020 study suggest that people taking rivaroxaban to treat deep vein thrombosis (a blood clot in a vein) do not experience increased fatigue.

Some people receiving ticagrelor may feel shortness of breath as a side effect. This symptom is common and often mild or temporary, and many people can continue the medication unless the breathing symptoms are severe or hard to tolerate, in which case a healthcare provider may consider an alternative.

A 2021 study found that clopidogrel can cause severe fatigue in some people. However, this side effect is very rare and only occurs in people who are more sensitive to clopidogrel.

Other Causes of Fatigue in People With PH

Fatigue caused by blood thinners could add to PH or PAH-related fatigue. A 2018 study found that almost 60 percent of people living with PH experience general fatigue. Some researchers believe decreased oxygen is the main cause of fatigue in PH. PH and PAH can make it harder for your heart and lungs to deliver oxygen to your brain and the tissues around your body, leading to mental and physical fatigue.

A 2018 study found that almost 60 percent of people living with pulmonary hypertension experience general fatigue.

Other causes of fatigue in PH and PAH include:

• Inflammation — Increased pressure in the pulmonary arteries can cause inflammation, which may lead to symptoms of fatigue.
• Lack of physical activity — Feeling fatigued can make engaging in physical activity and exercising more difficult. Without exercise, you may tire more easily.
• Sleep problems — PH is also associated with sleep problems such as insomnia and obstructive sleep apnea. A lack of restful sleep can also contribute to fatigue in people with PH.
• Associated conditions — Heart problems, other lung conditions, lupus, and liver disease can also contribute to fatigue in PH.

What To Do if You Experience Fatigue While Taking a Blood Thinner for PH

Talk to your doctor if you experience fatigue that doesn’t get better. They can help uncover the cause of your fatigue and help you find ways to improve it. The best way to fight fatigue is typically to treat the underlying cause. Your doctor may suggest different treatment options or lifestyle changes to control your PH and PAH symptoms, including fatigue.

Living with fatigue can be hard. The following tips may help:

• Eat a balanced diet and drink plenty of water.
• Get light physical activity when you can, under the advice of your doctor.
• Keep a fatigue diary to help you keep track of when you feel the most fatigued.
• Try meditation.
• Rest and conserve your energy when you can.
• Ask for help when you need it.

Blood thinners are an essential medication for people with CTEPH and some others with PH and PAH. Speak with your doctor if you experience any new side effects or symptoms, such as fatigue, while taking blood thinners. They may need to adjust your medication dosage or switch to a different type of blood thinner. By working closely with your healthcare team, you can manage your condition and figure out the source of your fatigue.

Join the Conversation

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Have you experienced fatigue while taking a blood thinner with PH or PAH? Let others know in a comment below.