Blood clots occur when the blood thickens to prevent excess bleeding, which is why scabs form on cuts and grazes. However, sometimes the blood can clot and form a blockage in a vein or artery. This can cause problems with the circulatory and respiratory systems, particularly if the clot becomes dislodged and travels into the lungs. For this reason, blood clots in the wrong place can have serious consequences for your health. If you suspect you have a blood clot, you should get medical advice immediately.
Unfortunately, blood clots can affect anyone. However, they are less common in those who are young and maintain a healthy lifestyle. Factors such as prolonged lack of movement, having an inflammatory condition or smoking can increase your risk of developing a blood clot. Another risk factor linked to blood clotting is taking the combined contraceptive pill.
The pill and blood clots
While the combined contraceptive pill is known to increase the risk of developing a blood clot, the risk remains very small. According to a Danish study, if 10,000 women with no history of blood clots used the combined pill for one year, around 6 would develop a blood clot of some kind. For those who don’t use the pill, around 3 in 10,000 would develop a blood clot in the same time period. If you don't have any risk factors for blood clots, your doctor is unlikely to advise against taking the combined pill. There may, however, be other reasons to choose a different type of contraception.
This is only a general overview of the subject. Your doctor's recommendations will be based on your specific medical history and circumstances. If they do suggest another type of contraception, it's important to listen. If you’re unsure about which contraception is right for you, your doctor or pharmacist will help you to understand your options.
Risk factors that may appear suddenly or increase over time include:
- Becoming overweight
- Significantly reducing movement - for example, if you have had an operation
- Some inflammatory conditions
- Using combined hormonal contraceptives
- You or a close family member having had a blood clot before
Why do birth control pills increase risk of blood clots?
One of the hormones contained in the combined pill is oestrogen. Oestrogen can affect the coagulant properties of your blood by increasing the concentration of clotting factors in your blood. Therefore, taking oestrogen every day increases your risk of developing a blood clot - although this risk is still very low.
It’s important to note that the combined contraceptive pill isn’t the only type of contraception that increases the risk of developing blood clots in this way. Any contraceptive that contains oestrogen can have a similar effect, including the contraceptive patch and the vaginal ring. If you’re unsure about your choice of contraception, ask if it contains oestrogen or may increase your risk of blood clotting.
Many forms of hormone replacement therapy (HRT) prescribed to women going through the menopause also contain oestrogen. This is used to replace the oestrogen that the ovaries stop making after menopause, however it can increase your risk of developing a blood clot in some types of HRT. When seeking HRT treatments, make sure your medical team is fully aware of any risk factors you may have so that they can decide which treatment is right for you.
Can the mini pill cause blood clots?
Currently, there is no evidence to suggest that the progestogen-only pill has any effect on your risk of developing blood clots. This includes desogestrel-based pills such as Lovima®, and the mini pill is generally considered a common alternative to the combined pill for those who already have risk factors for blood clots.
However, if you experience a blood clot while taking the mini pill, your pharmacist may recommend that you switch to another form of contraception instead as a precautionary measure. If you currently have a blood clot, you shouldn’t take Lovima®.
How to prevent blood clots on the pill
Although blood clots are rare, they can happen to anyone. However, there are plenty of things you can do to bring your risk levels down and make it less likely that you’ll develop a blood clot.
- Discuss contraception with your pharmacist
As previously stated, some contraceptives come with an increased risk of blood clotting. Switching to the progestogen-only pill or even a non-hormonal contraceptive such as condoms, a cap or the intrauterine device (IUD) may help to alleviate that increased risk. However, it’s best to discuss this with your pharmacist, as they can explain the risks and side effects of different types of contraception so you can make an informed decision.
- Maintain a healthy weight
Keeping a healthy weight not only helps to reduce your risk of developing blood clots, but it can also put less pressure on other systems of your body and reduce your risk of other conditions too.
- Get moving
Maintaining a healthy weight isn’t the only goal to exercising when it comes to blood clots. Moving your body, even if that simply means doing a short circuit of your home or office every few hours, helps to keep your blood moving and reduce the likelihood of it thickening into clots. If you can’t walk about, move your limbs in any way you can to stop the blood from staying in one place for too long. Wearing compression garments can also help.
- Stay hydrated
You’re more likely to develop a blood clot if you’re dehydrated, so make sure you’re getting enough to drink. Of course, this also has the added benefit of helping to prevent other conditions such as headaches.