Your doctor is right, you should be on hrt at least until your early 50s to protect your heart and bones. Osteoporosis isn't much fun either. Have a look at the Advice for Husbands pinned post, there are many symptoms caused by meno including aches and pains and fatigue. I had sore hips which I assumed were the joints wearing out but it went after I started hrt. Transdermal hrt is much safer than the older horse urine type that many of the scare stories are based on. Although there's a small increased risk with transdermal hrt it's less than if you drink, smoke or are overweight so you can reduce your personal risk by maintaining a healthy lifestyle.
