Dizziness with Standing

What might cause near blackout when getting up from a sitting position? I have chest pain off and on, but my doctors say that there is nothing wrong with my heart. They have not really investigated it. I have found that if I sit with my knees bent in anyway for any peroid of time and go to stand up I blackout. It seems to be happening more and more. I guess I am use to it since I have been dealing with it for years now and I have just given up that there is something wrong. Within the last year I started having muscle pains and I went from running a higher BP over 120 S/P every time checked to barely making it to 120 S/P. I get the same light headedness when I turn while an elevator is settling. My BP was checked maybe ten minutes after I got out of the elevator and it was at 96/P. Can BP change by close to 10 Systolic within a year and after a pregnancy. Is there any chance that these near blackouts cause muscle pains?

[cindy707]

Hi i read your post.  One of the main reasons for dizziness with or without heart problems is that your blood pressure is getting a little too low.  If a cardio doc ran tests on you and they came back neg. you need to look into other reasons.  Alot of times when we are at rest and suddenly stand up or get out of bed too fast because of the fast change in our  B/P is causes dizziness.  From what you've posted your blood pressure is well within normal limits and anything at all can make you dizzy from inner ear infections all the way up the ladder.  When you say you blackout does it seriously mean you lose consciousness and fall to the floor?  If that is the case you need to see someone immediately and if that was me i would have someone drive me to the E.R. immediately after i came to because that is something that is very serious.  The other issue here is when you say muscle pains are you talking about in your legs?  If so you also need to be checked to make sure you don't have a clot issue here.  There is a pretty wide span of b/p ranges and what is normal and i def. wouldn't be too worried out that part of it.....the elevator thing and dizziness when you are standing up after sitting is telling me this may just be something simple like an inner ear problem...like i said tho if you are truly losing consciousness i would run not walk to a doc ASAP  good luck

[grendslori]

Having problems with dehydration can also cause these types of problems.