Illness in a horoscope is covered by the 6th House (non-critical illness), the 12th House and its ruler (critical illness), the Ascendant degree and the Ascendant ruler (they are the physical body).
When someone is senior, especially beyond age 80, hard aspects (transit or Solar Arc) of Pluto, Neptune, or Saturn to any of the significators of the illness significators can be symbolic of illness and it can indicate a time of critical illness for seniors. Thee most difficult aspect there is is Pluto's hard aspect transit or arc to Saturn, especially if Saturn is in or rules the 12th House or Ascendant.
Unless a child has a bad relationship with a parent, their serious illness usually shows somehow in the horoscope through a heavy aspect. When my father passed, I had a SA MC-Mars contact. My mother died during my second Saturn Return.
Donald Trump will be 79 in June. He's getting up there. He has been well known to have poor eating and drinking habits. He will have SA Nep=Sun exact this coming December. The orb lasts from June 2026 to June 2027. In his horoscope, the Sun rules the 12th and the Ascendant. It's a serious contact for a senior with poor health food habits.
During this time, his family will have the following: Melania: transiting Pluto square the Sun and MC with TR Ura=Sun/Moon. The Sun/Moon midpoint is relational, like Venus. Barron will have transiting Pluto opposed Saturn (!!!) along with SP Moon crossing an Angle. Eric will have TR Pluto square the MC and TR Saturn square the Sun. Donald Jr., will also have TR Sat sq. Sun and SA Sat=Sun. They will all, especially Barron, will have some major tension during the period of time that the head of the family has a very challenging health picture. Barron's Pluto-Saturn is particularly ominous.
We'll see!