Gallstones (Cholecystitis) is a disease where stones become lodged in the gallbladder ducts. This can cause infection and inflammation with a great deal of pain. Around 75-80% of gallstones are known to ‘cholesterol stones’, the majority of the remainder are bilirubin pigment stones.
It is known that the risk of developing gallstones does increase with age (there is an urban myth that says they affect the ‘fair, fat and forty’), and they are more common in women, suggesting that there is a link between hormonal levels and the development of gallstones.
However, it does appear that taking HRT can increase the risk of developing gallstones, but the risk is slight (31 events per 10,000 women in a recent US Study).
The highest risk factor is amongst women who are taking an oestrogen only (usually post-hysterectomy) form of HRT as tablets. The risk is slightly lower for women who are taking a combined HRT (oestrogen and progestogen) and is lower in both instances if the HRT is given in the form of patches.