I had to look it all up again! So, Alex died on 12th December 2019, the day after Tammy's body was exhumed. He had had a very busy few months - he had shot and killed Charles Vallow 5 months earlier, on 11th July. About a month after that, late in August, Alex, Lori, the 2 children (plus Melani Boudreaux) moved to Rexburgh. Soon after, Tylee was last seen at Yellowstone NP on 8th September. On 9th September, phone records place Alex on Chad's property, where the children's bodies were later found. JJ was last seen when he attended school on 23rd September. On 2nd October, Alex is strongly suspected of having shot at Brandon Boudreaux. A week later on 9th October, Alex is also strongly suspected of shooting at Tammy Daybell. Not long after, on 19th October, Tammy died. This is now thought to be murder, either by Alex, Chad, or both. When Alex died on 12/12/2019, the children were still missing, and fear for them was growing. Melanie Gibb had told the police that Lori had asked her in November to lie about JJ's whereabouts. Lori and Chad had to fled to Hawaii. And now Tammy's death was being considered as murder. Things were unravelling. He was probably becoming very afraid.
So - after such a busy and no doubt stressful few months, it is not surprising his BP was way up. And yes, that can cause blood clots. Being a truck driver wouldn't help. Perhaps that is what happened. Perhaps not. But I would like to know who said he was having breathing difficulties, and if that was true. I also am not at all sure about Zulema, his new wife. Stranger things have happened than a woman being planted to find out if a murderer is having second thoughts. It is not impossible that Alex was considering confessing, betraying, suiciding, whatever. We may never really know.