Even though my father has retired, he is still tired.

Even though they no longer commute to work every day and are resting at home, they just lie down all day saying they are tired.

At first, I thought the fatigue accumulated from working was finally easing, but even though quite some time has passed since their retirement, they continue to be lethargic and lacking energy.

I am confused whether their physical strength has simply declined due to their age, or if there is something wrong with their body.

What should I do when elderly people like this remain lethargic and tired without a clear reason?

They do have some blood pressure due to their age, but it is not serious.