Co-stars described Williams as "frail", "small", and "uncharacteristically quiet."
After experiencing other failures, Robin started to develop symptoms like indigestion, sleep issues, trouble urinating, loss of his sense of smell, and heartburn. Then, he developed a slight tremor in his left hand, which had gotten worse over time. He lost weight, and his once-booming voice was softer. His former co-stars and friends said that he looked frail, small, and was "uncharacteristically quiet."
Photo source: Robin Williams by michelarouca