5 Times When Women are More at Risk of Blood Clots

Thrombosis, or blood clotting, can affect people of all ages, races, and genders. And while both men and women are at risk of getting a blood clot, there are several stages in a woman’s life when that risk may be higher.

Thrombosis is the formation of blood clots in the circulatory system, which can be dangerous if the clot blocks blood flow to vital organs, causing serious complications, such as deep vein thrombosis (DVT) or pulmonary embolism (PE).

According to the World Thrombosis Day (WTD) campaign, blood clots can happen to anyone at any time. Surgery, hospitalisation, and cancer raise the risk for everyone, but certain ages and factors in a woman’s life increase the possibility of getting a thrombosis.

Pregnancy

In general, women may be at a slightly higher risk of developing thrombosis during pregnancy and shortly after delivery. A woman’s body undergoes significant hormonal changes when she is pregnant, says Dr Helen Okoye, a leading Nigerian thrombosis specialist who is part of the World Thrombosis Day (WTD) steering committee.

“A pregnant woman’s blood becomes more prone to clotting to prevent excessive bleeding during childbirth, which places her at an increased risk of a DVT and PE. The risk of thrombosis remains elevated for a few weeks after childbirth. During this time, the body slowly returns to its pre-pregnancy state, and the risk of clotting decreases gradually,” explains Dr Okoye.

Hormonal contraceptives

Some forms of hormonal contraceptives, particularly those containing estrogen, can also increase the risk of blood clot formation, although the risk is generally considered low. Women who use combined oral contraceptives (containing both estrogen and progestin) or hormone-releasing intrauterine devices (IUDs) may be at a slightly higher risk of thrombosis.

Hormone replacement therapy

Hormone replacement therapy (HRT) involves taking hormones to alleviate menopausal symptoms and manage hormonal imbalances. Women undergoing HRT may have an increased risk of thrombosis, particularly if the therapy includes estrogen, says Dr Okoye. “Although the risk of thrombosis with HRT is generally low, it is higher than in women who are not taking hormone therapy. The risk may also be more for women who have additional risk factors, such as a personal or family history of blood clots, obesity, or a sedentary lifestyle. If you are using or considering HRT, discuss the potential risks with your healthcare provider,” advises Dr Okoye.

Medical conditions

Certain medical conditions, such as obesity and some inherited blood clotting disorders, can elevate the risk of thrombosis in women. Conditions that affect hormone levels, like polycystic ovary syndrome (PCOS), can also contribute to an increased risk of thrombosis, and some autoimmune disorders, such as systemic lupus erythematosus (SLE), which is much more common in women, can lead to an increased risk of blood clotting. Additionally, women with specific types of cancer may have a higher probability of getting a thrombosis.

Strokes

If a blood clot obstructs the flow of blood to a part of the brain, it can cause a stroke, the severity of which depends on the size and location of the blocked blood vessel.

Women have some differences in stroke risk compared to men, points out Dr Okoye. Stroke is more common in women than in men, with a 1 in 4 risk of stroke for women after age 25. Stroke is also the fifth leading cause of death for women, according to the Centers for Disease Control and Prevention (CDC).

Women, like men, can experience strokes at any age, but there are certain life stages and factors that can increase the risk of stroke in women. “Women tend to live longer than men on average, and stroke risk increases with age. Since stroke is more common in older individuals, the longer life expectancy of women contributes to their higher overall stroke incidence,” explains Dr Okoye.

Pregnant women, especially those with certain conditions like preeclampsia, gestational diabetes, or clotting disorders, may also have an increased risk of stroke.

The weeks following childbirth can also be a time of increased stroke risk for some women, particularly if they experienced complications during pregnancy or delivery.

Women who experience migraines with aura may also have a higher risk of stroke, especially if they have other risk factors such as smoking or using oral contraceptives. Atrial fibrillation is another red flag.

“This heart rhythm disorder is more common in women and significantly increases the risk of stroke due to the potential for blood clots forming in the heart and traveling to the brain. Hypertension is also a significant risk factor for stroke, and it can affect women at any age,” says Dr Okoye.

Lessen the risk

It is important to note that each woman’s risk of stroke or thrombosis is influenced by a combination of factors, including genetics, lifestyle, and medical history.

“Women need to be aware of their own personal risk factors and manage any existing health conditions they may have,” advises Dr Okoye. “If you’re concerned at all, consult a healthcare professional for personalised advice and risk assessment. Regular medical check-ups, adherence to prescribed medications, and a healthy lifestyle are all ways to reduce your risk of thrombosis,” she says.

“Strive to maintain a healthy weight. Being overweight or obese can increase the risk of blood clots, so follow a balanced diet that is rich in fruits, vegetables, whole grains, lean proteins, and healthy fats,” advises Dr Okoye. “If you smoke, stop as soon as possible. Smoking damages blood vessels and increases the risk of blood clots. And drink lots of water to keep your body well-hydrated, which can help prevent blood from thickening and forming clots.”

Staying active is crucial, too. According to the WTD campaign, regular physical activity helps improve blood circulation and reduces the risk of blood clots. WTD campaign’s  2023 theme is “Move Against Thrombosis”, and they advise people to incorporate exercise or regular movement into their everyday routine.

It’s important for women to be aware of all the above risk factors and what they can do about it, concludes Dr Okoye. “If you have questions about your risk of thrombosis, it’s essential to speak with your healthcare provider. They can assess your individual risk factors and provide appropriate guidance and preventive measures if needed.”

Finally, familiarise yourself with the signs and symptoms of blood clots, such as swelling, pain, tenderness, warmth, and redness in the affected area. If you suspect a blood clot, seek immediate medical attention.