Question: I have been experiencing shortness of breath that starts approx. 10 days before my menstrual cycle. The shortness of breath is more of a not being able to get a satisfying breath. I yawn constantly when this is going on. it is very uncomfortable, and a bit scary. Then as soon as I start my period, the symptoms go away. It always happens just before my period. My doctor has done lab work which all came back normal, except my WBC's were 17,000. I have had a D-dimer, chest X-ray, Stress test, allergy testing, EKG, MRI of brain, and multiple labs drawn, that all come back normal. The shortness of breath does not happen before every period, but when it does, I experience horrible bleeding. The bleeding is not normal, it is all clots between the size of a blueberry and a grape. I know I am not anemic, although my iron is on low side of normal. I know it's not asthma, although i do have exercise-induced. I know it is not Von willebrand's, i have been tested (because I once had a period for 5 weeks straight) Now if you need my past med Hx to help, I am 30years old, overweight, but have changed my diet and eating habits (all very healthy, nothing dramatic) since thanksgiving and have lost 40 lbs. i have exercise induced asthma. Although I am a large girl (280lbs) I am pretty healthy, my BP usually runs 105-100/65-75. I do experience orthostatic BP on occasion. I am allergic to cats and plant mold. I have hypermobility disorder, I have PCOS and suffer from infertility. When this shortness of breath occurs my SpO2 is always 98-100%. My family is all very healthy. My parents take no medications, both of my grand parents passed at an early age (war, and car accident). My paternal grandmother has arthritis and my maternal grandmother passed away of an unknown illness that mimicked cancer, but was not cancer, It attacked her brain, she had multiple brain surgeries before dying. doctors are unsure what she had, because they had neverr seen anything like it. it sounds crazy but she went to ED for excessive hicups, was admited, was transferred to multiple hospitals including OSU, Cleveland clinic, and Mayo clinic before passing away. No one could diagnose her. My great grandfather (my maternal grandmother's father) had a blood disorder that was discovered late in life (in his 80's) doctor's told him it was not serious, but my family is unsure of what it is. I am an LPN who works for multiple family providers. When this shortness of breath occurs, they always listen to my lungs, and they are always normal. Nobody has a clue what this is? Any ideas?