Knew a lady who grew up in my neighborhood and she was bucked by a horse. She then began having difficulty breathing and was rushed to the hospital. She had a P.E. and the horse knocked it loose and it exploded in her lung and sadly she past. 29 y/o.
Now with Serena Williams she had foot surgery and had been wearing a cast for some time. She developed a deep vein thrombosis in her calf and it traveled to her lung. So steroids was probably not the cause but if she was taking them then it greatly increase the risk but with her I am sure she was flying and traveling all around and being on a plane is not recommended after surgery. These clots develop in the leg from immobility.
Remember Derrick Thomas LB Chiefs.. This is exactly what he died from. Paralyzed and lost feeling and mobility in lower extremities. Developed a clot in his legs that traveled to his lungs. Now that was a travesty because I think he was in a rehab center at the time. I would have to think he was on Heparin injections. But in his case he could not tell a person he was having pain cause of the paralysis.
The symptoms would of been Swelling, Redness/Discoloration, Warmth, and lack of Pulses. This should have been noticed by medical staff. DVT is a bit harder to find with a black person than a white person because the discoloration is much more evident but the nurses should of been performing regular pulse checks and lower extremity observations for swelling and warmth. Just my rant on Derrick Thomas.