For about 8 months or longer I've been experiencing joint pain, GI problems like nausea, occasional vomiting, and stomach aches. I've always had dizzy spells when standing up most of my life, and have only fainted a few times after standing up. Almost every day after standing up my vision goes black and I have to sit down before getting up slower. I measured my heart rate when laying down and standing. Laying down my HR is around 70-85. When I stand up, it spikes up to about 140 then levels out to about 120 after 10 minutes and blood pooling starts in my feet. After a while of standing, it goes down to about 110 but I still have discomfort and tingling in my legs.