Complex sentence: Her health gradually deteriorated in the final two decades of her life; a heavy smoker for most of her adult life, she had a lung operation in 1985, a bout of pneumonia in 1993, and at least three strokes between 1998 and 2001.
Split into simpler sentences: Her health gradually deteriorated in the final two decades of her life. A heavy smoker for most of her adult life, she had a lung operation in 1985, a bout of pneumonia in 1993, and at least three strokes between 1998 and 2001.