Blood Clots, Menopause, and HRT: What to Know

Hormonal changes during menopause can affect more than just menstrual cycles. They also influence cardiovascular health, including the body’s tendency to form blood clots. Some women may notice changes in circulation and clotting patterns as hormone levels fluctuate during menopause. Understanding how menopause and hormone replacement therapy (HRT) intersect with blood clot risk is an important part of making informed choices about symptom relief.⁽¹⁾

Blood Clots During Menopause

Blood clots are gel-like clumps of blood that form in response to injury or to prevent excessive bleeding. Normally, this process helps protect the body, but hormonal fluctuations during menopause, particularly changes in estrogen, can disrupt this balance. Estrogen plays a role in regulating clotting factors. Shifts in estrogen levels may lead to an increased tendency to form clots, especially in those with additional risk factors.⁽¹⁾⁽²⁾

Age-related changes in vascular health also play a role. As the body ages, blood vessels may become less flexible, and circulation can slow. This natural shift, paired with a more sedentary lifestyle that’s common in midlife, can increase the risk of deep vein thrombosis (DVT), where clots form in the deep veins of the legs. DVT can be serious if a clot breaks free and travels to the lungs, causing a pulmonary embolism.⁽²⁾⁽³⁾

Additional risk factors during menopause include smoking, obesity, genetic predispositions, and prolonged immobility. These factors can combine with hormonal changes, making some women more susceptible to clot formation. The risk may be slightly elevated for those with underlying conditions like high blood pressure or diabetes.^(1)(2)(4)

Fluctuating hormone levels during perimenopause can lead to menstrual irregularities, including heavier bleeding with tissue-like clumps or menstrual clots. These clots are formed from the shedding of the endometrial lining and are not the same as blood clots associated with conditions like DVT. Heavier bleeding with menstrual clots is particularly common in the later stages of perimenopause, when hormonal changes become more pronounced. Although this is often a normal part of the transition, it may still warrant medical evaluation to rule out underlying causes such as fibroids or endometrial abnormalities.⁽⁵⁾

Estrogen’s Role in Blood Clotting

Estrogen influences several clotting factors in the blood, which can make clot formation more likely. When estrogen levels rise — whether naturally or through external sources like HRT — the liver increases the production of proteins involved in blood coagulation. This change can tip the balance in favor of clot formation in some individuals.⁽¹⁾⁽⁵⁾

Different types of estrogen can also affect clotting risk to varying degrees. For example, synthetic estradiol, a form of estrogen used in many HRT products, has been associated with increased clotting activity in the bloodstream. This doesn’t mean every woman on HRT will develop a clot. In fact, clotting risk is still considered low, but it highlights the importance of selecting the right kind and route of therapy.⁽¹⁾⁽³⁾

Recognizing Signs That May Indicate a Risk

Some symptoms may indicate a potential blood clot and should be taken seriously. The following are just a few points to be aware of:

• Sudden leg swelling, especially in one leg

• Pain or tenderness in the leg, often starting in the calf

• Red or warm skin over the affected area

• Unexplained shortness of breath

• Chest pain that worsens with deep breathing

• Rapid heartbeat or lightheadedness

These signs could indicate DVT or a pulmonary embolism and require immediate medical evaluation.⁽²⁾⁽⁴⁾

HRT’s Role in Blood Clotting

HRT can influence clotting risk depending on the type and delivery method. Oral HRT, especially tablets containing estrogen, has been linked with a higher risk of blood clots due to its effect on the liver’s production of clotting proteins. Research shows that oral estrogen increases the risk of venous thromboembolism (VTE) more than non-oral routes.⁽¹⁾⁽³⁾

Transdermal HRT — delivered through skin patches, creams, or gels — has a lower risk profile. These methods bypass the liver and do not significantly affect clotting production. Micronized progesterone, often prescribed alongside estrogen, appears to carry a neutral or even protective effect on clot risk when compared to synthetic progestins.⁽¹⁾⁽³⁾

Everyone responds differently to hormone therapy. While HRT may increase clot risk in some, it also provides meaningful relief from menopause symptoms and supports long-term health in others. A personalized approach, guided by a menopause-trained physician, can help women weigh the benefits against the potential risks.

Managing Risks and Making Informed Decisions

It’s important to understand that an increased clotting risk does not mean a blood clot will occur; it simply means hormonal changes may amplify any existing risk. The following are considerations to keep in mind to manage risk factors:

• Discussing personal and family history of clotting disorders with a physician

• Choosing transdermal HRT options when appropriate

• Maintaining a healthy weight and active lifestyle

• Avoiding smoking, which compounds clotting risks

• Managing blood pressure, cholesterol, and blood sugar levels

• Scheduling regular check-ups with a menopause specialist

• Seeking prompt care for symptoms of clotting or abnormal bleeding

Can women take HRT if they have a higher risk of a blood clot?

Women with a known predisposition to blood clots — including a personal or family history of DVT, pulmonary embolism, or genetic clotting disorders like Factor V Leiden deficiency — are usually advised to avoid systemic HRT. The added estrogen can raise their clotting risk further, particularly in the first year of therapy.^(1)(3)(6)

However, this does not mean HRT is entirely off the table. In many cases, alternatives or tailored approaches allow symptom relief without unnecessary risk.

A thorough, in-person evaluation by a menopause specialist can help identify the safest and most effective treatment plan. Testing for clotting tendencies and reviewing cardiovascular health are key steps in that process.

HRT and Heart Devices: What to Consider

Women with medical implants or devices related to cardiovascular health — including pacemakers, coronary stents, cerebral shunts, or artificial heart valves — require special consideration when evaluating hormone therapy. These devices often indicate a history of serious cardiovascular conditions that may already increase clotting risk.⁽⁷⁾

In these cases, HRT must be approached with caution. Oral estrogens are not usually appropriate due to their effect on clotting pathways and liver metabolism. Transdermal estrogen, which does not significantly increase clotting factors, may be a safer alternative. However, any decision about HRT in this population must be made in collaboration with both a menopause specialist and the patient's cardiologist. The most important step is a personalized plan built around a woman's unique health history and current needs.

The Safest Route

Menopause and blood clot risk can be complex, but women have support in the process. With continued research and individualized care, HRT can remain a valuable option for many. Choosing the safest route — especially with guidance from trained professionals — can offer symptom relief without unnecessary compromise.