Boots WebMD Partners in Health
Return To Boots

Menopause health centre

Blood clots and HRT

BMJ Group Medical Reference

Blood clots are one of the most serious problems linked to taking hormone replacement therapy (HRT), but the increased risk is very small for most women.

When you get clots in your blood, doctors say you have thromboembolic disease. Although it isn't dangerous in itself, it can become life-threatening if a clot travels through your blood and blocks an important blood vessel. If a clot stops blood getting to your lungs, it is called a pulmonary embolism, which can kill you.

Researchers have found that women who take HRT are twice as likely to develop thromboembolic disease as women who don't take HRT.[79] However, the risk of thromboembolic disease is small to begin with, so the increased risk for women who do use HRT is still not very big.[51][21] In one large study: [21]

  • Over a period of about five years, less than 1 in 100 women taking HRT got a blood clot in their lungs

  • This was about twice the number of women who got this type of blood clot when taking a dummy treatment (a placebo) for comparison.

A big review of the studies found that the risk of blood clots was increased for women taking combined HRT tablets (oestrogen and progestogen) and for women taking oestrogen-only HRT tablets.[91] But women who took HRT in the form of patches had no increased risk of blood clots.

If you've had blood clots before, you should let your doctor know and talk about whether HRT is suitable for you.

Glossary

placebo

A placebo is a 'pretend' or dummy treatment that contains no active substances. A placebo is often given to half the people taking part in medical research trials, for comparison with the 'real' treatment. It is made to look and taste identical to the drug treatment being tested, so that people in the studies do not know if they are getting the placebo or the 'real' treatment. Researchers often talk about the 'placebo effect'. This is where patients feel better after having a placebo treatment because they expect to feel better. Tests may indicate that they actually are better. In the same way, people can also get side effects after having a placebo treatment. Drug treatments can also have a 'placebo effect'. This is why, to get a true picture of how well a drug works, it is important to compare it against a placebo treatment.

pulmonary embolism

A pulmonary embolism can give you chest pain, make you feel breathless and uncomfortable or make you breathe rapidly. A pulmonary embolism is dangerous and can kill you if it is not treated.

For more terms related to Menopause

Citations

For references related to Menopause click here.
Last Updated: March 25, 2013
This information does not replace medical advice.  If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.

Women's health newsletter

Health news, features and tools for your life
Sign Up

WebMD Video: Now Playing

boots-menopause-myths.mov

Menopause symptoms

From hot flushes to mood changes: learn how to manage and treat menopause symptoms.

Popular Slideshows & Tools on Boots WebMD

woman looking at pregnancy test
Early pregnancy symptoms
donut on plate
The truth about sugar addiction
woman holding hair
Natural help for dry or damaged hair
woman in bikini
Get ready for swimsuit season
hand extinguishing cigarette
13 best tips to stop smoking
Immune-boosting foods
The role of diet
79x79_not_good_for_you.jpg
18 secrets men want you to know
boy looking at broccoli
Quick tips for feeding picky eaters
hamburger and fries
A guide for beginners
salmon dinner
A diet to boost your mood & energy
polka dot dress on hangar
Lose weight without dieting