London, Sep 4 : Many women are unaware that taking higher doses of hormone replacement therapy (HRT) may increase the risk of womb cancer, according to a study. While the HRT containing oestrogen is safe when taking the correct, prescribed dosage, women often tend to take very large doses of the drugs to tackle menopause symptoms, Daily Mail reported. Oestrogen is a female sex hormone which decreases with age, causing most of the symptoms of menopause such as hot flushes, mood swings, and brain fog. HRT use is further spiked by social media messages that encourage taking more medication to reduce these symptoms. According to Cancer Research UK, oestrogen-only HRT increases the risk of womb cancer. "This increased risk gets bigger the longer HRT is used, and may stay for some years after HRT is stopped. This is why it is usually only prescribed to people who are not at risk of womb cancer. "Oestrogen-only HRT is usually only given to people who have had their womb removed (hysterectomy)." The report cited research from gynaecological cancer charity The Eve Appeal, which found that most women are unaware of the risks of taking too much oestrogen. The charity said its survey -- which polled 2,000 women in the UK -- shows a need to educate women about the link between excess oestrogen and womb cancer, which affects almost 10,000 women each year. "Roughly one in ten women on HRT are taking two or even three times the maximum dose," Dr. Katie Barber, who runs a GP-led NHS gynaecology service in Oxfordshire, was quoted as saying. "Safety studies into HRT in these doses have not been done." Typically, women are prescribed HRT drugs in patch, gel or spray form and the drug, containing compounds similar to hormones oestrogen and progesterone, is absorbed through the skin. Some say excessive amounts of the compounds can trigger anxiety, palpitations and mood swings. Patients can also suffer tachyphylaxis -- where they need more and more hormonal treatment to feel normal. If taken in high doses for a long period, oestrogen and progesterone not taken in the right balance may cause womb lining to thicken -- known as endometrial hyperplasia. This can lead to heavy bleeding and increase the risk of womb cancer, the report said. Excess oestrogen can also be caused by health conditions such as obesity and polycystic ovary syndrome (PCOS), and has also been linked to ovarian and breast cancer. "Factors which increase the level of oestrogen in the body -- conditions such as PCOS and medications such as HRT -- therefore increase the risk of these cancers. Being aware of this and learning how to reduce this risk is lifesaving," Dr Aziza Sesay, a GP who works with The Eve Appeal, was quoted as saying. /IANS