I'm not sure what is going on but lately I have been getting lightheaded. My best hypothesis is a pulmonary embolism or heart problem. My breathing seems normal, I just had a bit of a sharp pain in my left rip that lasted a moment, could have been gas, could have been a pulmonary embolism. If I do have a pulmonary embolism it wuold be very unlucky for me as I had just had a d-dimer test one at the hospital that came back negative, that should indicate I do not have a PE unless something went wrong with the test, I did notice the nurse had trouble getting blood from me and did not have a full vial. Anemia is a potential although at the moment I feel light headed yet in the mirror do not look pale. Also my blood pressure seems normal so it would likley be autoimmune or iron related rather than hemoraging. At the moment I am leaning towards a heart issue or perhaps anemia. Salt seems to be a trigger for it as well as after exercising and after masturbating, the odd part is that it comes on AFTER excercise. Another significant factor is that I seem to have symtpoms that arise from standing up from sitting. This causes tightness in throat and chest, palpitations, throbbing temple vein and full feeling in left rib cage. The light headedness seems to prodominate at night and be fine in the morning, therefore may be also related to fatigue. I'm not sure what to make of all this, I can't see any clear patterns for diagnosis other than it could perhaps be my heart, and a lesser likelihood PE. Also lately I get a cold sensation when I breath in. I'm not sure if this is significant, I believe I have had this symptom before and attributed it to acid reflux. Tomorrow morning i will test myself for diabetes, it probably is not a factor but it is something I can do immediately. I can't go to emerge and say I feel light headed. The cool sensation seems to be a product of acid reflux according to the internet, which makes sense. At the moment I am having erectile dysfunction, I find that odd as I've never encountered this issue before, this could be an indicatoin of heart problem along with the lightheadedness. Although again I can't go into the ER and say I'm having lightheadedness and erectile dysfunction, what's wrong with me.