How would you know if you have them? A friend of my husband recently passed away; she had a lot of blood clots and it gave her a heart attack. She was only in her 40s.
I'm worried because I'm on HRT and I'd like to know what to look out for.
You really can't "look" for anything. You may have clots that don't cause any problems. Then if one goes to the heart and clogs up something important, you have a heart attack. If it goes to the brain, you may have a stroke.
Clots in the legs will cut off important circulation. But usually, you don't know ahead of time if you have one.
Talk to your doctor about your worries. They are always coming up with something new in medicine. It may be that they have recently developed some kind of magic test the will detect them before they cause problems.
A friend found out last week that he has blood clots on/in his lungs. He went to the hospital because of tremendous pain. He was given blood thinners and sent home because the chance of getting an infection at the hospital was deemed to be so high as to be gravely dangerous for him.