It's an ill family...
Queen Mother Sirikit - Debilitating severe stroke in 2012, hospitalised multiple times since with bladder, lung, etc infections. Likely suffering from dementia. Extremely frail for the last five years but currently impressively stable, miracle that she's still alive.
King Rama X - US cables said he was suffering from HIV/Hepatitis C and blood cancer in 2009, in ICU with "respiratory problems" last year. I wouldn't be suprised if he dropped dead suddenly, people with such lifestyles usually don't see 75+.
Princess Sirindhorn - Ill with heart diseases since atleast 2019. Undergone a lot of treatment.
Princess Soamsawali - Two strokes in 2019, other ailments.
Princess Chulabhorn - Systemic lupus, pancreatitis in 2014, sometimes has inflammations/infections, stomach problems...
Princess Bajrakitiyabha - currently gravely ill with heart problems.
Chakriwat Vivacharawongse - neurofibromatosis.
+ Induratana Paribatra - ex-royal, centenarian. Not made appearances since around 2017 when she was already in quite frail health.
+ Bandhu Savali Kitiyakara - mother of Princess Soamsawali. Wheelchairbound and very frail for atleast ten years.