Dizziness and migraine when laying down on stomach

Age: 18

Gender: Female

Height: 5’8

Weight: 180

Smoking status: Never

Previous/Current medical issues: Had mono in the past, low iron

Medication: None, just iron supplements

Hi, I was wondering if someone had an answer to my problem I’ve had for awhile now. So basically, when I go from standing up to laying down on my stomach, I get very dizzy suddenly. My ears usually pound, I see spots in my vision, my heart rate increases, I feel sick, and I usually end up getting a migraine shortly after. It doesn’t matter the speed I lay down with, fast or slow, this happens. This doesn’t happen when I lay down on my back, only my stomach, so I try to just lay on my stomach. I have tried to research why this is? I thought it could just be because of my history of having low iron, but I never see anyone have issues with laying down specifically, only standing up. Any insight would be appreciated.

Thank you