I’ve never heard it called “bad tension” but I have POTS (postural orthostatic tachycardia syndrome) which fits your symptoms. I can’t maintain my blood pressure when I stand still (or if I get too hot, bend down, lift my arms over my head, eat a big meal…) my heart rate skyrockets to try to compensate and I ultimately faint.

I was diagnosed in 2012 and they’re still tweaking my medication to try and get it right. For most people it starts in their teenage years and they “outgrow” it within 5 years. For me it’s second to moderately severe Ehlers Danlos Syndrome, there’s no outgrowing it. I can’t go anywhere that requires more than a short walk from the car to a seat - queues are literally my enemy - so I use a wheelchair. The amount of dirty looks I get when I get out of my wheelchair to move to a more comfortable seat, or to go to the toilet etc are awful! Not only are a lot of disabilities invisible but not everyone who uses a wheelchair can’t walk at all. Grrrr!